Carlos Alcaraz says ankle injury is better ahead of Indian Wells title defence
The Spaniard, who trounced Daniil Medvedev in last year's final in the California desert, had to retire after two games of his match in Rio de Janeiro after twisting his right ankle.
It was the latest setback for the world number two, who has not won a title since beating Novak Djokovic in the Wimbledon final last July.
He lost in the quarter-finals of the Australian Open in January and was beaten in straight sets by Nicolas Jarry in the semis of the Argentina Open last month.
He rallied to defeat Rafa Nadal in an exhibition match in Las Vegas on Sunday, and while he said he has been feeling good during his practices he knew there would be a question mark about his injury.
"Probably some of the people are thinking about my ankle, let's see if I'm going to say 100% or not, but I'm feeling better," he told reporters.
"So let's see how the tournament is going to go but I'm here to defend, I'm not thinking of anything else."
After a ceremony where a mural commemorating his title last year was unveiled on the grounds, the two-time Grand Slam champion said he was still adjusting to fame.
"A lot of days you wake up not in a good mood and you want to hide or not be recognised by people," he said.
"But I'm a natural guy and I try to take it as natural as I can. The people know me, recognise me, and I think that's good."
The tournament's second seed will kick off his title defence on Friday against Matteo Arnaldi.