Federer will play on clay for the first time in three years next month when he competes at the Madrid Masters.
With his last match on the surface back in 2016, Federer has been getting himself reacquainted with his coaches Severin Luthi and Ivan Ljubicic and fitness trainer Pierre Paganini.
Last week, Federer was spotted working with rising Serbian player Miomir Kecmanovic.
And according to The Times, Federer had Evans come and work with him this week.
Evans lost in the first round of qualifying for the Barcelona Open to Marcel Granollers and was therefore available to be called upon.
Federer and Evans have a friendly relationship and that was evidenced at the Australian Open in January.
The Swiss star beat Evans in three tight sets and said afterwards: “It felt like playing in a mirror a little bit.
“That was the mindset I had – how would I play myself potentially.”
Evans is continuing to make his rise up the rankings after a 12-month ban for testing positive for cocaine.
Speaking last month to the New York Times, Evans said he was keen to move on with his life following his suspension.
“Listen, that episode in my life of being banned, it’s over,” Evans said.
“Everyone forgave me as soon as I held my hands up and accepted the blame.
“But it’s not easy to be happy with yourself day in and day out when the fact is, I was No. 41 in the world and I threw it all away.
“But to say that I’ve grown, that would be justifying it. There’s no sort of philosophical looking back on it. It was the worst thing ever.
“Now, I’m just back trying to win tennis matches.”