Tennis great Roger Federer admits he’ll be entering the unknown when he faces Great Britain’s Dan Evans in Monday night’s Hopman Cup clash at Perth Arena.

The match will be Federer’s first since undergoing knee surgery six months ago, and the 17-time grand slam winner says there’s a very real prospect he’ll be rusty.

“I mean it’s a little bit of the unknown,” Federer said.

“I have been playing probably 20-plus sets in the last four weeks, so I kind of know where I’m at.

“I’m really here just to see what’s going to be working in my game and what’s not.

“It’s about just getting into the rhythm and groove. Not getting injured is obviously most important.

“I’m just really happy I can play tennis again, I can play points.”

Federer hopes his recent injury lay-off will allow him to play on for another two or three years.

The 35-year-old will partner former world No.7 Belinda Bencic in Perth.

Bencic faces world No.76 Heather Watson in the women’s singles rubber.

Like Federer, Bencic’s 2016 campaign was blighted by injuries, with wrist and back issues seeing her slide down to 43 in the WTA rankings.

Switzerland are the favourites to win the Hopman Cup, and Federer said he was excited to team up with Bencic.

“She’s an up and coming star. She’s had a tough year herself as well, injuries this year. I hope for both of us this next year is going to be much better,” Federer said.

“She’s very talented, and hard working. I don’t know her that well yet, but after this week all that’s going to change.”