Juan Martin del Potro believes only his fitness is stopping him from competing with the world's best after his US Open run came to an end in the quarter-finals.
The Argentinian suffered a 7-6 (7-5) 4-6 6-3 6-2 defeat to third seed Stan Wawrinka at Arthur Ashe Stadium on Wednesday.
His career once threatened by wrist injuries, Del Potro won silver at the Rio Olympics before reaching the last eight in New York.
After his best major performance since Wimbledon in 2013, the 2009 US Open champion is upbeat about his form.
"I think my tennis is starting to respond as I want, but physically I'm still down," Del Potro said.
"I'm not on the same level as these guys. I need to just to stay healthy and wait for the pre-season to get 100 per cent for next year.
"I'm already top 100, so that's good. Never will I ask for a wildcard anymore. And everything here is positive for me. I'm so glad for that."
Del Potro was almost brought to tears as the crowd showed their appreciation before Wawrinka served for a semi-final meeting with Kei Nishikori.
The 27-year-old, exhausted at match's end, said he was just about happy to forget his loss, thanks to the fans.
"It's something difficult to describe with words. I mean, I can lose the match, but I will never forget this. You know, it's bigger than to win any match," Del Potro said.
"I'm so proud to get that from the crowd, because I have been doing a big effort to play tennis again. They made me so happy tonight, and I don't mind the score."
Next for Del Potro is likely to be the Davis Cup, having been named by Argentina to face Great Britain in their semi-final in Glasgow.