Roger returned to the court in Doha today ahead of the Qatar Open, which begins later this week.
“For me, tennis is like riding a bike, I always knew that I could play very little and still play very good,” Federer said.
“My biggest concern is the knee. I’ve had two knee surgeries, I had to build from scratch.
“The next 3-5 months are going to be interesting, how the knee is gonna react. I’m not sure my knee will hold up.
“But I’m confident, otherwise I wouldn’t be here. The knee will dictate what my comeback looks like.
”If I can pull off a couple of matches here in Doha, I’ll be happy.
“The expectations are very low. I hope I can surprise myself.
”I’m not sure my knee will hold up, but I’m confident, otherwise I wouldn’t be here.”