Murray will play his first Grand Slam in more than a year on Monday when he takes on Australia’s James Duckworth in the first round of the US Open.
The Brit’s last appearance at the highest level of tennis came at Wimbledon last year, after which he took six months off to allow a chronic hip problem to recover.
However, that was unsuccessful and he had surgery to correct the issue in January from which he is still struggling to regain full fitness.
But Gilbert, Murray’s coach for the 2006 and 2007 seasons, believes his former charge still has a long road to full recovery ahead of him.
“He needs a full year of being healthy to play a lot, to see what he can do,” Gilbert said
“I’m sure that like all of a sudden he’s not the kind of guy that like, man, I’m hoping to be able to win a couple and can get into the tournament by getting through the first week and go from there.”
The 31-year-old has won just four matches this year but produced an impressive run to the quarter-finals of the Washington Open that included a three-set win over Marius Copil that left him sobbing into a towel on court.
Murray subsequently pulled out of the semi-final with fatigue but the run still represented a significant step-up from his ultimately unsuccessful Wimbledon prep that included an Eastbourne win over Wawrinka.
The Swiss had two knee surgeries last year and spent the first half of the year losing matches than he was winning.
But he reached the quarter-finals of the Cincinnati Masters before squandering a one-set lead to Roger Federer, pointing to a gradient of progress to which Gilbert reckons Murray should pay close attention.
“I saw Stan [Warwrinka] a couple of months ago, and he didn’t look very good when he played Murray before Wimbledon,” Gilbert added.
“And then all of a sudden I see him in Cincinnati, and he’s completely a different player.
“So I do think that with Andy’s ability, once he’s healthy and can play week in and week out, the results are going to come.
“If in 12 months from now, if Andy was totally healthy, no more injuries, and you told me he was back in the top five, I wouldn’t be surprised.
“But he’s just going to need time.”
Murray will also have an outstanding example of a lengthy recovery across the net from him next week in Duckworth.
The 26-year-old had foot surgery at the beginning of last year and even briefly slipped outside the top 1,000 in the rankings.
It means Murray will, remarkably, be the higher ranked player – his No 378 in the world to Duckworth’s No 445 – and the winner is guaranteed a Spanish opponent in the shape of either Fernando Verdasco, the No 31 seed, or Feliciano Lopez.