Roger Federer
Andre Agassi has backed Roger Federer to play for at least another four or five years Getty

Andre Agassi has backed Roger Federer to continue playing on the ATP Tour for at least another 'four or five years' after the former world number one surprised everyone by making a strong comeback from injury in 2017.

The Swiss ace spent six months on the sidelines with a knee injury in 2016 and failed to play a single tournament since his loss in the semi-finals at Wimbledon. Questions were raised about his future in the game and his ability to challenge for Grand Slam titles – he had not won a major tournament since 2014.

Federer, however, surprised everyone and himself by winning his 18th Grand Slam at the Australian Open which was his first ranking tournament in six months. He followed it up by winning the Indian Wells and Miami Masters titles and is currently on a 19-1 win-loss run.

The 35-year-old has made it clear that staying fit and focusing on major tournaments is the plan for 2017. He dismissed any question of retirement, by signing a deal to play his home tournament in Basel until at least 2019, when he will be 38 years old. Agassi, however, believes the current world number four can go on for longer.

"No no. Coming back I would have probably called it a career before. Every tennis player has a different career and each one has his reason to retire. In my case my body had told me to stop and I didn't have other choice. Also, I never had Roger's game," Agassi said when asked if he could have prolonged his career after seeing how Federer is doing it, as quoted by tennisworldusa.org.

"For me it was easy, but it seems that he can keep going for another four or five years. The only thing I can say is that when the end comes, it comes in a fast way and you do not expect it. Something happens and everything changes," he added.

'I needed a break'

Federer is currently on a ten-week break after playing four tournaments since the start of the year. The former world number one has chosen to skip the upcoming clay court tournaments in Monte Carlo, Barcelona, Madrid and Rome and will only return for the French Open beginning on 22 May.

The Swiss star has insisted since the start of the season that he will not play as many tournaments as before and will focus on peaking at the major events. Wimbledon and US Open are his main targets in 2017.

"In Dubai I realised that I needed a break. After Indian Wells and Miami, I understood that playing in the clay season would have been too much," Federer said, as quoted by tennisworldusa.org.