Stan Wawrinka has no regrets at the start of his farewell year on the ATP Tour, saying he "squeezed the lemon until the last drop."

Wawrinka announced last month that he would retire from tennis at the end of 2026, with this the final season of a glittering career that has included three grand slam victories.

He won the Australian Open in 2014, the French Open in 2015 and the US Open in 2016, with his best Wimbledon runs ending at the quarter-final stage in 2014 and 2015. 

Wawrinka is one of only four players to have defeated each of the 'Big Three' – Roger Federer, Rafael Nadal and Novak Djokovic – at grand slams, alongside Andy Murray, Tomas Berdych and Jo-Wilfried Tsonga.

Wawrinka has been handed a wildcard for the Australian Open, which begins on Sunday, and at the age of 40 years and 290 days, he will become the oldest wildcard entrant in the men's singles at the event in the Open Era.

Wawrinka has battled knee and foot injuries for several years, sliding to 139th in the ATP Rankings, and though he wishes he could play pain-free, he believes he got the absolute maximum out of his talents. 

"Of course, I would love to play more freely," Wawrinka said in an interview with The Guardian. "Sometimes I tell myself; 'Just play freely.' 

"But I care so much that it's not that easy. At the end, I really believe that I squeezed the lemon until the last drop. 

"And that, for me, is the most important thing, because that's the only way I can leave this sport without any regrets. 

"There's always some small regrets; 'In that match, I should have done better,' or whatever. In general, I don't have regrets, because I know that I did the most with it."

40, 290 - At 40 years 290 days, Stan Wawrinka will be the oldest wildcard entrant in the Men's Singles at the Australian Open in the Open Era. Swansong.#AusOpen | @AustralianOpen @atptour @ATPMediaInfo https://t.co/c8IP3IvGfv

— OptaAce (@OptaAce) January 10, 2026

Wawrinka won a gold medal at the Beijing Olympic Games in 2008, playing doubles alongside Federer, with the Swiss pair also teaming up to win the 2014 Davis Cup.

Federer dominated his head-to-head with Wawrinka, boasting 23 wins to three losses, though one of Wawrinka's victories came in the Monte Carlo Masters final in 2014 and another came in the last eight at Roland-Garros in 2015, when he lifted the trophy.

But Wawrinka believes the fact that his breakthrough came at the height of Federer's powers only served to elevate his game.   

"I'm always someone who's going to take the positives from a situation, and I only got positives by arriving [after Federer]," says Wawrinka. 

"Roger was already at the top, and I had the chance to share time with him, to share practice, to talk about tennis, to play the Davis Cup with him for so many years, to win a gold medal with him, to face him. 

"Even if he beat me most of the time, he put me in a position to see my weakness and how I should get better."