Sampras would have liked his chances of beating Federer in their primes, with their one meeting involving the latter shocking the former at Wimbledon in 2001.
Federer would end his career with 20 Grand Slam titles, with Sampras having won 14, behind the 24 of Djokovic and 22 of Nadal.
Novak Djokovic is prioritising Grand Slams this season, although he failed in his early efforts after falling in the Australian Open semi-finals.
It was a step further than he managed at the 2014 Australian Open, a tournament in which Sampras was asked to compare the likes of Federer and Nadal and indeed himself and legendary figure Rod Laver.