Since the Nitto ATP Finals moved to London in 2009, only three Americans have qualified for the season finale. Andy Roddick punched his ticket in 2010 and Mardy Fish booked his spot a year later. This time, it’s John Isner’s turn.

The big-hitting North Carolina native is playing the best tennis of his career, and at the age of 33 he is the oldest first-time qualifier since 1972. Isner, who appeared at The O2 as an alternate in 2015, is relishing the opportunity to finally compete in the big show.

“It means a lot to be here,” Isner told the assembled media at The O2. “I’ve been very close throughout my career. It just hasn’t quite happened. I also realize that I’m pretty fortunate to be here as well this year. That said, I’ve had a very good year and I put myself in position to make this event. And at 33, to be competing in my first Nitto ATP Finals is very satisfying. This is certainly a life-changer, all for the good. My wife and daughter are here as well, so it’s very special.

“I think over the last 9-10 years I’ve been very consistent. I’ve been between No. 10 and No. 19 that entire time. But this year, it wasn’t so much that I was super consistent with my results. It was that I had 3-4 big results. The way our ranking system works, that’s often what it takes to get to the Top 10 and stay there. For me, it all started in Miami. I was actually 0-6 prior to that and I turned it around with one tournament. It’s what great about tennis. It only takes one event to turn things around and get it to go your way.”

Isner joins a long list of Americans who have qualified for the crown jewel of the ATP calendar, including legends Jimmy Connors, John McEnroe, Pete Sampras and Andre Agassi. It has been more than a decade since the nation had a player reach the final. In 2006, James Blake finished runner-up when the tournament was held in Shanghai. And it has been nearly two decades since an American lifted the trophy. Sampras last achieved the feat in 1999, when the event was staged in Hanover, Germany.

When asked if any of the more recent American competitors have offered advice, Isner acknowledged that Fish spoke to him after learning of his qualification.

“I did speak to Mardy at length about the experience,” Isner added. “Everything he said is true. He absolutely loved his time here and told me how cool an event it is. I got a little taste in the past when I was an alternate, but it’s a big difference to be a part of the real thing. 

“This is the pinnacle of the ATP calendar for sure. To have it at the end of the year with all these great players is amazing for me. I’ve seen it on TV and the atmosphere is incredible. London puts on such an amazing event and I’m happy to be a part of it.”

Isner is undoubtedly enjoying a career-year in 2018. In April, the 33-year-old lifted his maiden ATP World Tour Masters 1000 trophy in Miami, earning a trio of Top 10 wins over Marin Cilic, Juan Martin del Potro and Alexander Zverev. And in July he registered his best result in a Grand Slam, when he battled to the semi-finals at Wimbledon. That was immediately followed by a fifth crown at the BB&T Atlanta Open.

But those standout results, also including a quarter-final finish at the US Open, was nearly not enough to qualify for the season finale. Sitting in 10th position in the ATP Race To London, Isner claimed his spot among the elite eight when both Del Potro and Rafael Nadal withdrew due to injury. The American was sitting at home in North Carolina when he got the call. 

“I knew there was a good shot I’d be here, but I went back home from Paris for four or five nights. I went back home on Saturday and I found out on Monday that I was in. I flew here on Wednesday night. It’s maybe a little bit unorthodox. Most players stay in Europe after Paris, but I felt it was a pretty nice break for me. Even if it was for just a few days, to be back home with the family and sit on the couch and watch football, there’s a lot to be said for that. It relaxes you.

“Physically, I feel great. I’ve been very fortunate throughout my career to be injury-free. Of course there are a few things that pop up, but there’s nothing that has sidelined me for an extended period of time. I continue to work hard on my body, which is the most important thing I can do. As long as I can stay healthy, at 33, I do feel pretty good. For me personally, seeing a guy like Roger, even though he’s from another planet, he’s still doing incredible things at 37. It’s very encouraging for me to see that. It gives me a lot of incentive to keep working as hard as I can.”

Isner finds himself in the same group – Group Guga Kuerten – as World No. 1 Novak Djokovic, third seed Alexander Zverev and fifth seed Marin Cilic. He opens his campaign against five-time champion Djokovic on Monday night.

“I’m up against it for sure. Novak has won this event five times. He’s the player to beat this week for sure, and he’s back to No. 1 after an incredible second half of the year. It’s a good spot for me, because I don’t have much to lose. I’m definitely the underdog. 

“I’m going out there to play my best and be lose and free. I’ve played him eight or nine times and I’ve beaten him a couple, but he’s beaten me more times than I have. It’s going to be a very tough match, but I’m looking forward to it. The atmosphere is going to be great and it’s going to be a big challenge.”

Appearing at the Nitto ATP Finals for the fourth time, Marin Cilic is well aware of the challenges ahead of him as he attempts to advance beyond round-robin play for the first time at the elite eight-man event.

The 30-year-old, who began his season by reaching his third Grand Slam final at the Australian Open (l. to Federer), will begin his campaign against German Alexander Zverev on Monday afternoon, with a strong start crucial as he hopes to win his opening match at the tournament for the first time. Joined in Group Guga Kuerten by Novak Djokovic and John Isner, Cilic will be aiming to overcome the disappointment of three-set losses in each of his round-robin matches at The O2 last season.

“Small margins are going to make the difference,” said Cilic. “Playing the top guys is always a big challenge and matches against them are always very close and very tight.”

With a 1-8 record in his previous three appearances, Cilic will be eager to get off to a good start in a city where he has enjoyed success in recent years. Earlier this year, the 18-time tour-level titlist saved one championship point to overcome Novak Djokovic in the Fever-Tree Championships final. Cilic also reached the championship match at Wimbledon in 2017 (l. to Federer).

“This year I feel that I am prepared well and I am feeling good physically as well,” said Cilic. “I feel, mentally, quite fresh and ready for the challenges. I feel these experiences, from previous [appearances], will help me prepare better.”

After early losses in Tokyo, Shanghai and Basel, Cilic rediscovered his best form at the Rolex Paris Masters last week. The 6’6″ right-hander defeated Philipp Kohlschreiber and reigning Nitto ATP Finals champion Grigor Dimitrov, before ending Novak Djokovic’s 30-set winning streak in a three-set loss to the eventual runner-up.

“In Paris, last week, I played great tennis,” said Cilic. “I am feeling good at the moment and [I am] very excited.”

With experience and form, Cilic could finally be set to show his best level at the season finale. But he, as well as the rest of the field, knows it will likely come down to the smallest of margins.