Federer enjoyed a sensational 2017 campaign, winning seven titles including the Australian Open and Wimbledon.

The 36-year-old’s year ended in disappointment when he was beaten for the first time by David Goffin at the season-ending ATP World Tour Finals.

Federer is scheduled to open this 2018 campaign at the Hopman Cup in Perth before moving to Melbourne to defend his Australian Open title.

In a picture posted on his Twitter account, a bearded Federer is standing opposite his long-time fitness Pierre Paganini.

The 19-time Grand Slam champion, who is holding a medicine ball in a sweat-drenched shirt and smiling at Paganini, wrote in the tweet: “Gym time.”

Federer credited Paganini for his work in helping him recover from knee surgery which hampered his 2016 season.

In an interview with the New York Times in November, Paganini believed Federer had the ability to continue playing for several years.

He said: “I think only Rog will know when it’s the moment that he’ll want to say perhaps this is enough.

“Rog does have the biological age of 36 but for me, he has an athletic age that is younger than that and yet he has the maturity of someone well over 40. 

“So it’s quite a balance. And because of that it’s very difficult to say or predict. 

“It’s the man who makes the decision, not just the athlete, unless there’s a serious injury that leaves you no choice.”