Andy Murray is not playing at Wimbledon this year as he continues his recovery from a hip injury, but he has been at the All England Club this week and will be co-commentating for BBC Sport on Wednesday.

In his regular BBC Sport column, the 31-year-old Scot talks about his fitness, his preparations for the American hard-court season, why he thinks Novak Djokovic can win Wimbledon, and not asking Tim Henman for commentary tips…

Not playing Wimbledon was the best decision I could have made – I have no regrets about it.

Last year I came in when the hip was bad, managed to get through to the quarter-finals but ended up missing a whole year because of it.

I didn’t want to go in this year, potentially play four or five matches, and do any damage.

Obviously I was very disappointed I wasn’t able to play, but I wasn’t going to win the tournament and I wasn’t well enough prepared.

It was a hard decision but a smart one.

The positive things were being able to spend some more time with the family while I’m here at home, and being able to practise on the hard courts.

As soon as I got on the hard courts I felt better. When you’re coming back on an unstable surface you worry about every step.

So I felt more comfortable and hopefully that will help my movement and free up the hip. The impact on a hard court is greater than on grass but it felt more positive.

My plan is to play in Washington, which starts on 30 July.

I’m going to be here in London for the next 10 days, practising on the hard courts, and then I’ve got a friend’s wedding.

I’ll be going to that and then heading over to the States, having a week’s training either in Washington or maybe Miami before getting back on the match court.

Feeling better than I did at Queen’s

I’ve been practising since last Monday, so when the tournament started it felt a bit odd because I was practising about 10 minutes away in Raynes Park.

I feel good and a lot better this week than I did at Queen’s a couple of weeks ago, so that’s positive. Hopefully it keeps going the same way.

I’ve not been playing more sets than I was in the run-up to Wimbledon, I’ve just been getting used to the hard courts again.

I practised with Thanasi Kokkinakis on Tuesday and I’m practising with Jeremy Chardy on Wednesday so I have got some good sessions lined up over the next few days.

Then hopefully I will start playing more sets towards the end of next week.

Conditions perfect for Rafa

I’ve been following the Championships, of course, although I thought it would be harder watching than it has been.

I haven’t watched every match but when I’ve finished my training I’ve watched a lot – I saw Juan Martin del Potro playing Gilles Simon, Rafael Nadal against Jiri Vesely, Kyle Edmund against Novak Djokovic – pretty much each day I’ve watched some and seen what’s going on.

The conditions are perfect for Rafa right now.

When it is hot like this, the courts are hard and the ball bounces up so he gets more movement with his serve as well. With the problems he’s had with his knees, the ball bouncing up higher makes it is easier on his body too.

In the top half of the draw, Roger Federer has a brilliant record against all of the guys. He looks like he is playing extremely well and he is moving well.

Djokovic winning Wimbledon would not surprise me

Novak could beat both Roger and Rafa. From what I have seen in the past couple of days, he looks to be playing really, really well.

He’s not been in the latter stages of major events so much recently, Queen’s was his first final in almost a year and it looked like he had doubts in that match against Marin Cilic.

But I think his level is back to where he wants to be and mentally he is where he needs to be.

Novak said the mental side has been difficult for him. Last year he suffered from a slight dip in motivation which is normal because of what he achieved in 2016, when he won the French Open to complete the career Grand Slam.

It must take an incredible amount out of you. Winning the French Open must have been huge for him but then where do you go next?

Maybe the injury and being away from the sport helped him realise how much he misses it and what it means to him.

It wouldn’t surprise me if he went on to win this tournament.

I tell Henman he talks rubbish on TV!

On Wednesday I will be commentating on one of the men’s quarter-final matches for BBC TV.

I’ve done bits and pieces on radio before but not a whole match. I’ve not had any tips from Tim Henman – I would get tips off someone different. From one of the experts!

I’m always messaging him when he’s commentating, telling him he’s talking rubbish! Of course, that’s a joke.

Who is my favourite commentator? I like listening to Mark Petchey. I know him well, he coached me, and I think he is knowledgeable about the game.

I’ve not had any tips from him either – I might give him a text later. I’m a bit nervous about it to be honest.

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Britain’s Jamie Murray and Brazilian Bruno Soares were knocked out of the men’s doubles in the quarter-finals after a five-set thriller at Wimbledon.

The fifth seeds led twice against Raven Klaasen and Michael Venus before dropping serve twice in the final set.

Play was suspended after Murray and Soares won the fourth set tie-break while the roof covered Centre Court.

The match lasted more than four hours before the 13th seeds won 7-6 (7-5) 6-7 (5-7) 7-5 6-7 (4-7) 4-6.

Murray is still aiming to defend his mixed doubles title after reaching the third round with Belarusian and former world number one Victoria Azarenka.

The Scot won the event at Wimbledon and the US Open with now-retired partner Martina Hingis last year.

• Williams into women’s semi-finalss
• Kerber to face Ostapenko in semi-finals
• Del Potro sets up Nadal quarter-final
• Has Djokovic rediscovered his mojo?

Meanwhile, Britain’s Joe Salisbury and Dominic Inglot progressed to the semi-finals with victories in their quarter-finals.

Salisbury and Denmark’s Frederik Nielsen will play South Africa’s Klaasen and New Zealand’s Venus in the semi-finals after they defeated 14th seeds Ben McLachlan and Jan-Lennard Struff 7-6 (8-6) 4-6 7-6 (7-2) 7-6 (7-4).

Inglot and Croatian partner Franko Skugor defeated Robin Haase and Robert Lindstedt 6-3 6-7 (2-7) 7-6 (7-1) 6-4 and will face former world number one Mike Bryan and fellow American Jack Sock in the semi-finals.

British 15th seed Inglot has won three outdoor ATP titles in 2018 but had not gone further than the third round at Wimbledon prior to this year.

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Elsewhere, compatriots Jay Clarke and Harriet Dart are in the quarter-finals of the mixed doubles after they comfortably defeated Mate Pavic and Gabriela Dabrowski 6-3 6-4 in the third round.

But British 16th seed Heather Watson and Finland’s Henri Kontinen were knocked out in the third round by third seeds Ivan Dodig and Latisha Chan after losing 2-6 6-7 (4-7).

Ten years ago, Roger Federer and Rafael Nadal contested a Wimbledon final which many believe is the greatest tennis match ever played.

Now aged 36 and 32 respectively, the top-seeded pair are each two wins away from a romantic rematch.

But first they have to negotiate their quarter-final matches on Wednesday.

While Federer, Nadal and fellow all-time great Novak Djokovic are old hands at reaching this stage, there are three debutants in the SW19 quarter-finals in Kevin Anderson, Kei Nishikori and John Isner.

Meanwhile, 2016 runner-up Milos Raonic and 2009 US Open champion Juan Martin del Potro are in familiar territory.

Here, with the help of two-time Wimbledon champion Andy Murray, BBC Sport looks at how the last eight men standing match up…

• Has Djokovic rediscovered his mojo?
• Live scores, schedule and results

Roger Federer (Swi) [1] v Kevin Anderson (SA) [8]

Federer’s progress through the draw has been smooth and serene, not dropping a set nor losing a service game on his way to an Open era record 53rd Grand Slam quarter-final.

Another straight-set win over Anderson will see the Swiss great better his record run of 34 consecutive sets at SW19, which he enjoyed between the third round in 2005 and the final in 2006.

“I don’t think it’s something anybody aims for, to win every match in straight sets,” Federer said.

“I hope I get off to a good start, go from there. If it happens, it happens.”

Anderson, 32, is one of the biggest servers on tour and the hot conditions are helping his game. However, the 2017 US Open finalist has never taken a set off Federer in four previous meetings.

Andy Murray’s verdict: “Roger is playing well and moving well, and against Anderson he leads 4-0 in their head-to-head. So I feel comfortable he would get through.

“It would take an unbelievable serving performance from Anderson. If he serves 80% first serves and Roger has a really bad serving day, then he might have a chance.”

Milos Raonic (Can) [13] v John Isner (US) [9]

A battle of the big servers is likely to see plenty of baseline rallies and not much court-craft.

Between them, Raonic and Isner occupy the top two places in the ace count and fastest serves standings.

Isner has a higher percentage of landed first serves than anyone else, while only Federer has won more points on his first serve than Raonic.

“There’s a good chance it’s going to come down to a few points here and there,” said Isner. “It’s strength on strength, for sure.”

Raonic has the greater experience at Wimbledon, however, reaching at least the last eight in four of his past five appearances here – including a run to the 2016 final where he was beaten by home favourite Andy Murray.

“It’s a surface that’s going to allow me to come forward more,” he said. “It’s going to help my volleys when I’m at the net stay a little bit lower, these kind of things.

“It’s harder for other guys to move. If they’re not moving as well, it’s hard for them to be in balance for passing shots.”

Andy Murray’s verdict: “This is tie-breaks. Isner is 3-1 up head to head and that’s a bit surprising for me. Raonic is maybe a little bit more comfortable on the grass than John but that is an impossible match to pick. I wouldn’t want to bet on that one.”

Novak Djokovic (Ser) [12] v Kei Nishikori (Jpn) [24]

To claim Djokovic is back to his 12-time Grand Slam winning best would be a tad premature, but the 31-year-old Serb is getting closer to it.

The three-time champion, who has not reached a Slam semi-final since the 2016 US Open, clinically despatched Karen Khachanov in the last 16 and will be considered favourite to beat Nishikori.

Djokovic has beaten the Japanese 24th seed in 13 of their 15 meetings.

“So far four matches have been really, really good for me,” said Djokovic, who eliminated British number one Kyle Edmund in the third round.

“I haven’t spent too much time on the court. I feel physically, mentally ready, fit, positive.”

Former world number four Nishikori, who has never faced Djokovic on grass, has lost twice to him this year on clay.

“It’s always like a big war for me,” said Nishikori on facing Djokovic. “It’s always a big challenge.”

Andy Murray’s verdict: “In terms of his level and the way he’s playing, I think Novak is back to where he wants to be. Mentally he looks where he needs to be – looks fired up and motivated. He’s got a great shot.”

Juan Martin del Potro (Arg) [5] v Rafael Nadal (Spa) [2]

Like his great rival Federer, Nadal has reached the last eight without dropping a set.

The 32-year-old looks refreshed following his decision to pull out of Queen’s and now, unlike Del Potro, has had the benefit of a day off.

Del Potro was forced to finish his last-16 match against Gilles Simon on Tuesday because of fading light on Monday, but said afterwards he felt he would be in a “good condition”.

The Argentine is one of the most popular players among tennis fans, not least because he has had to overcome serious wrist injuries which left him contemplating retirement.

But he persevered through dark times and is rewarded with his second successive Slam quarter-final – the first time he has done that since reaching the last eight at both the Australian Open and Roland Garros in 2012.

The fifth seed lost to Nadal in the Paris semi-finals last month, however.

“It will be a different match that we played in Paris few weeks ago,” he said. “I will try to hold my service games most of the time.

“If I want to beat him, I have to come to the net very often and play hard with my forehands, with my backhands, and try to take all the chances.”

Murray’s verdict: “Nadal faces a tough match against Del Potro. If Del Potro is physically there – I saw some of his match against Gilles Simon on Monday and he seemed to have some issues – that’s not an easy match.”

Federer makes rare appearance on Court One

Eight-time champion Federer will play on Court One for the first time since the 2015 quarter-finals, with former world number one Djokovic’s match against Nishikori put on Centre.

The Serb has only played once on Centre this year – his third-round win over Edmund.

He has played twice on the 11,000-capacity Court One this year, and once on the 4,000-seater court two for his second-round clash against Horacio Zeballos.

Murray’s verdict: “Rafa and Del Potro has to be on Centre – that is the best match of the quarters.

“The fans on Court One will love seeing Roger and while some ticket holders on Centre might be upset, they have two brilliant matches to look forward to.”

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