Switzerland's Roger Federer returns the ball
Switzerland's Roger Federer returns the ball to France's Richard Gasquet during their Davis Cup final singles tennis match at the Pierre-Mauroy stadium in Villeneuve d'Ascq, near Lille, November 23, 2014. Reuters

Australian coaching legend Tony Roche has said that 17-time Grand Slam Swiss champion Roger Federer, whom he has coached before, still has a good few years left in him. Roche gave a positive viewpoint on Federer's future and said that the Swiss can definitely add another slam in his long list of achievements.

"I think he (Federer) can play as long as he wants on the mental side," Roche told the reporters during his special training camp in India. "Physically, I think he can play for another four - five years without any problem."

Roach, who has won 13 Grand Slam titles in his illustrious tennis career, said that Federer will undoubtedly win another Slam. Federer last won a Slam in 2012 at the Wimbledon Championship. Roche is certain that Federer can win another Grand Slam trophy and he thinks Wimbledon is Federer's best chance. However, Roach added that Federer is "knocking on the door in last few Slams."

According to Roche, Federer is the most clever tennis player in history. He recalled the days when he used to work with the Swiss and said that his smooth skills come naturally. Roche said that Federer's advantage is that he is able to stay healthy and injury-free. He said that it is the way Federer hits the tennis ball. Unlike other tennis athletes, Federer does not exert too much physical effort when hitting serves and volleys.

Wrist, lower limb and upper limb injures are common in tennis, and Roche said that Federer is blessed because he didn't go through any serious injuries over the years. It was in March 2013 when Federer sustained a back injury that made him drop from the second to the sixth spot in the world rankings.

Roche has previously coached Ivan Lendl, Novak Djokovic, Patrick Rafter and Lleyton Hewitt. The 69-year-old Wagga Wagga native has started his seven-day training camp at Jaydeep Mukherjee Tennis Academy on Dec. 1, Kolkata Today reports. Indian tennis star Somdev Devvarman and Davis Cup players Saket Minani and Sanam Singh are among Roche's students in the said training camp.

Meanwhile, Federer is slated to make his first appearance in India for the International Premier Tennis League, or IPTL, matches from Dec. 6 to Dec. 8. It will be the third leg of the IPTL team tournament.