Mark Petchey says Andy Murray is still targeting winning big titles, and if he felt he couldn't he would have already retired.
Petchey coached Murray earlier in his career, and last week he returned to the Scotsman's team in an advisory role.
Murray is not playing in the Rome Open, but he has travelled to the tournament for some practice sessions with top players, including world number one Novak Djokovic.
According to Petchey, though, just playing tennis is not good enough for Murray in the long run - he wants to get back to winning important competitions.
"He needs to get everything right," Petchey told Amazon Prime during their Rome Masters coverage.
"And as much as the fitness side is a big thing because of the hip, this is still very much a skill-based sport.
"His skill level isn't in doubt in many people's eyes, but without the bulk of matches that you have and the point of reference, you've got to get that right.
"Hits like this with Novak [Djokovic] are obviously huge for him, because he's got the ability to feel the ball coming from Novak's racket, to play points against him and see what he's able to do."
Murray's attempts to make a sustained comeback to the ATP Tour have so far all stalled, but Petchey says the overall goal has not changed - and that goal is titles.
"Winning [a big event], that's it," he said. "Winning is the goal for him.
"That's the reason he's putting in the work he is that I've seen in the gym and the court and the intensity he brings to practice sets and everything else.
"If he didn't feel that he could do that, he would put his racquets away.
"Obviously it's a very tough task ahead of him with the situation he finds himself in, but if there's anybody that can take the 'im' out of 'impossible', it's him."
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