Sampras is in Melbourne to present the Norman Brookes Challenge Cup to the winner of the men's singles on the 20th anniversary of his first Australian title.
It seems likely he will also be marking the moment when Nadal equals his tally of 14 grand slam titles, with the Spaniard due to face first-time finalist Stanislas Wawrinka on Sunday.
When Sampras won his 14th title at the US Open in 2002 to set a new record, it seemed inconceivable that within 12 years not one but two players would equal or surpass it.
Federer leads the way on 17 titles but he is nearly five years older than Nadal, and the Spaniard would be the youngest player to reach 14 should he defeat Wawrinka.
He would also be the first man in the Open era to win each slam at least twice.
The evidence is certainly mounting in Nadal's favour, not least his record against Federer, and he recorded a 23rd win from 33 meetings in the semi-finals on Friday.
But Sampras said: "I believe when you look at the history of the game, each decade has its player. Let's just appreciate what we're watching.
"These are two of the greatest players of all time playing in the same decade. Certainly it's not going to last forever."
Sampras is good friends with Federer and hinted strongly that he would have liked to see the 32-year-old reach the final in Melbourne.
But he is a big admirer of Nadal as well, and had no doubts the Spaniard would be more than just a great clay-court player.
"I knew he was going to be great because he's a great athlete," the seven-time Wimbledon champion said. "His game is not suited to grass, but he's done well there.
"The great players adjust to different surfaces. When you watched him play as a youngster, he was an incredible mover. He figured it out."
Although Federer's campaign ended in familiar fashion, the positive news for the former world number one was the form he showed in beating Jo-Wilfried Tsonga and Andy Murray.
After struggling during 2013, Federer is free of back pain and appears rejuvenated by a new racquet and a new coaching partnership with Stefan Edberg.
Sampras played Edberg 14 times, and he said: "I think it's a good match. Stefan is a great guy. He knows the game. He's very relaxed. He'll be good for Roger.
"Roger's obviously a great player - he's won 17 majors. Sometimes you just get to a point where you need to hear a different voice."
Sampras retired following his last US Open win and largely stays away from the tennis circuit.
He revealed he has been approached to join the ranks of former greats returning as coaches but has no wish to do so.
"It's not for me," he said. "I've been asked by a couple of guys. But the travel, to go on the road, do all that they're doing, is not something that I'm interested in."
In the decade since Sampras played, the dominant style in the men's game has changed completely, with the vast majority of players much more comfortable at the baseline than the net.
"For the most part it's just everyone staying back and throwing rocks," Sampras said.
But the American does not buy into the argument that racquet and string technology, coupled with the supreme athleticism of players, means coming to the net is too difficult.
"Why wouldn't I?" he said with a smile when asked whether he would serve and volley in today's game.
"That's the only way I know how to play. People say it's harder to do it, but I think technology would have helped me out.
"I think serve-and-volley tennis would have been just fine today. You just need to know how to do it."