New York - Rafa Nadal is "a beast" on the court who capable of overtaking Roger Federer as the all-time grand slam king, Pete Sampras said Thursday.
"If he's smart with his schedule and the fact that he has so many at such a young age, he could very well do it," Sampras told reporters on a conference call.
The 24-year-old Spaniard claimed his ninth grand slam crown by winning the US Open earlier this month and became the seventh man to complete a career grand slam in the process.
Federer holds the record for most major titles with 16, having eclipsed the previous mark of 14 set by Sampras.
"The only question with Rafa is physically how much his body can handle the pounding with how hard he works for every point. You just watch him play, the kid is relentless," said Sampras, promoting an exhibition against his old rival Andre Agassi at Madison Square Garden in February.
"It's a huge goal, it's a lot of majors, a lot of work."
When asked whether Nadal needed to pad his resume to cement his place among the sport's all-time greats, Sampras said, "Quite honestly I don't think he needs to."
"He's won all the majors. He's won the Olympics. He's dominated his main rival, in Roger," Sampras said, referring to the Spaniard's 14-7 head-to-head edge over the Swiss master.
"I don't think his goal is 16, or 17 or 18, he's just going to try to improve as a tennis player and if it happens, great.
"He could do it, it's a lot of work ahead and he works so hard in every match he plays. But he's a beast."
That does not mean Sampras is dismissing the 29-year-old Federer's chances of adding to his own total.
"He's a strong favorite for every major he plays. He had two match points against (Novak) Djokovic," Sampras noted about Federer's five-set loss to the Serbian in the US Open semi-finals.
"He could very well have been in the final. He's playing fine, I don't see any big decline. Other guys are playing better. The next two or three years is a challenging time.
"But Roger is up to the task and can win more majors."
Sampras would not be drawn into a debate about the best of all time.
"Everyone wants to name the one guy. The way I look at all sports, especially tennis, is that each generation has their own guy.
"In the '60s it was Laver, you had Ivan (Lendl) and John (McEnroe) in the '80s, myself and Andre in the '90s. It's hard to answer. It's just that each decade has their guy," said Sampras, later throwing the likes of Bjorn Borg and Don Budge into the mix.
"But Rafa is definitely up there. You got to definitely put him in the top three or four just on what he's been able to do and it's not over yet. He's in the middle of his career so he can do a lot more great things."