However, the Brit thinks Novak Djokovic faces a totally different challenge as he also recovers from injury.
Both Murray and Djokovic are out with respective hip and elbow injuries and will not feature again this season.
That was after a stellar 2016 for both men, who met in two of the Grand Slam finals that year.
Murray decided to take a break to recover from his hip problem after crashing out of Wimbledon this summer.
Djokovic has also not played since Wimbledon, where he lost in the quarter-finals to Thomas Berdych.
In their absence Roger Federer and Rafael Nadal have swept up the sport’s biggest prizes in 2017.
And Rusedski reckons there’s a distinct difference in the pair’s injuries and that Djokovic could struggle to return to his former spot as World No 1.
“Andy Murray, for me, it’s not mental, it’s physical,” Rusedski said on Sky Sports.
“If the body comes back and the hip is fine and he can get himself physically fit again, and everything is firing, he will be in the mix to win majors again.
“Djokovic, for me, however, with the elbow injury – it’s such a mental question mark. He was the best player bar none when he held all the four majors [at the same time] – which no player had done since Rod Laver.
“The fall from grace he has had has been incredible – that to me is mental and that can be more difficult [to overcome] sometimes than a physical injury.”
Both Nadal and Federer have greatly impressed this year despite their age.
Federer, 36, added the Shanghai Masters title to his Wimbledon and Australian Open triumphs last weekend.
And Nadal, who lost the Shanghai final, added the French Open and US Open to his Grand Slam haul.