And Cash believes that it is Djokovic who will emerge with the all-time record for major titles.
"As a shotmaker I would say [Federer is] the greatest player I have even seen,” Cash added. "In shotmaking and movement and everything else. But in court surface and in many ways, he has been little old school.
"He has developed a more attacking game on surfaces and balls that really don’t suit him.
"It’s phenomenal for that record he has, but Djokovic has the best record of them all and is closing in."