former world number one Pete Sampras has said that 17-time Grand Slam winner Roger Federer could play for another four years.
According to Sport24, Sampras is impressed with Federer's devotion towards tennis.
Sampras said Federer should be comforted by the fact that his winning streak ended with a defeat to current world no 1 Rafael Nadal, adding that the Swiss player could win another Grand Slam title if he plays his best tennis.
The report said that after a disappointing 2013 season due to back problems, Federer took 2014 by storm under his new coach Stefan Edberg, reaching the final of his first tournament this season at Brisbane and then made to the semi-finals of the Australian Open for the 11th consecutive year.
Meanwhile, Federer has hinted that he may continue to play tennis until the Rio Olympics in 2016 showing his love for the game.