Tennis great Andre Agassi has labelled rising Japanese star Kei Nishikori one of the `greatest shot-makers’ in tennis history and tipped him to win grand slams.

“He was one match away from US Open,” the former world number one told AFP after going toe-to-toe with Nishikori in an exhibition event in Tokyo.

“Probably the biggest reason for (not winning the title) was the physical wear and tear over the course of the tournament, and sometimes that’s a bit unlucky.”

“There is no question in my mind he believes he can win a slam,” added Agassi, 44, who won eight grand slam titles before retiring in 2006.

“I’ve seen him play with that purpose. From a talent perspective, he’s very capable of winning a grand slam. He’s dynamic and incredibly fast.”

Agassi, who smacked several eye-popping shots past Nishikori before going down 8-6 in an abbreviated match, insisted Nishikori had the weapons to topple the game’s big three of Novak Djokovic, Roger Federer and Rafael Nadal.

“He beat Djokovic on the way to the US Open final, and if he did it once he can do it again,” said the flamboyant American, tipping Nishikori to be at the forefront of any changing of the guard in men’s tennis.

“What he’s done is very impressive in this day and age to do the way he does it. Kei is one of the greatest shot-makers the game has ever seen and there’s no reason he can’t go on further.”

Agassi, famous for his punishing training routine, warned Nishikori about the dangers of burn-out, however, offering some sage advice on physical preservation to a player who was plagued with injuries earlier in his career, most notably in 2009 when he feared he might not play again after undergoing elbow surgery.

“I know how hard you have to work to make it look easy at times,” Agassi said.

“Being number one and doing it over the course of a career requires good decision-making, not just talent. He’s somebody who has to be mindful of his body, so that he’s healthy all year.