Ivan Lendl insists Andy Murray can still compete for grand slam titles after re-joining the Scot's coaching team for a third time.
Lendl has teamed up with Murray in order to prepare the two-time Wimbledon champion for his home grand slam this summer, with the 34-year-old skipping the clay-court season to enhance his chances of being at his best on the grass.
Murray won all three of his grand slam titles, Wimbledon in 2013 and 2016, and the US Open in 2012, under Lendl's guidance, but has not reached a grand slam quarter-final since 2017, undergoing two hip surgeries during that time.
Lendl, who himself won eight grand slams during a glittering playing career, cited Rafael Nadal's victory in January's Australian Open as evidence that class remains permanent, and expressed confidence in Murray's ability to follow his lead.
"You are asking this [whether Murray can compete] with a straight face after what Rafa [Nadal] has done in Australia," Lendl said after watching Murray's second-round defeat to Daniil Medvedev in Miami.
"They are just like bulldogs, and they want to do things because they haven't been done before.
"If they set their mind to it then they can achieve amazing things.
"Rafa said he wasn't even sure he's going to be able to play again [after his own injury problems], then he goes and wins the Australian Open. So yes, these guys can do it.
"I would say grass is probably Andy's best surface.
"[For] a lot of the players, it's their worst surface. That would obviously increase his chances."
Murray made his first ATP final since 2019 earlier this year, losing in straight sets to Aslan Karatsev in the final of the Sydney International in January, and is 85th in the ATP world rankings.