Reigning US Open champion Novak Djokovic plays for his 13th Grand Slam title in New York next week.

Djokovic's childhood tennis hero, 14-time Grand Slam champion Pete Sampras, suggests it will be tough for the 29-year-old Serbian to surpass Grand Slam king Roger Federer's all-time record of 17 majors.

Watch: Top 5 Reasons Djokovic Will Break Federer's Record

While Sampras calls Djokovic a "dominant" champion, who will top his own major mark, he told The New York Post "it's a big question" whether the six-time Australian Open champion can break Federer's record of 17 Grand Slam championships.

“He’s got a very good chance of tying and passing me at some point,’’ Sampras told Marc Berman of The Post. “Whether he could get to Roger Federer, it’s a big question. He needs to stay healthy and continue to be motivated. The last couple of years, he’s been incredibly dominant.’’

The Hall of Famer believes 18-year-old Taylor Fritz could be the next great American men's champion.  

"Taylor’s got a good future,’’ Sampras told The Post. “It’s a cycle and we’re not quite what we used to be in the ’80s and ’90s. I’ve hit with him. He’s a nice kid who is doing all the right things.”

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