Stan Wawrinka is aiming to compete at the Australian Open in January even if he is still short of full fitness.
The Swiss ended his 2017 season prematurely in August due to a knee injury, rendering him unable to defend his US Open crown and preventing him from competing in the ATP World Tour Finals.
A three-time grand slam singles champion, Wawrinka's first major success came at Melbourne Park in 2014.
And the 32-year-old is determined to feature at the tournament in January as he continues his rehabilitation.
"I had problems with this knee since the Basel tournament in 2016," he told L'Equipe.
"My only regret is not having stopped my grass [court] season earlier, which has only aggravated the situation.
"Today, I'm working with my physio six days out of seven. The goal is to play the Australian Open, even if I'm not 100 per cent."
Wawrinka split with coach Magnus Norman in October and the timing of the Swede's departure was a cause of significant frustration for the former world number three.
"It was a big disappointment, a shock," he said.
"In the most difficult moments of a career, one should be able to count on the closest ones."