Former Swiss tennis star Marc Rosset says he is unsure if and when will Roger Federer come back but acknowledged that a great champion should never be underestimated. Federer, 40, underwent two knee surgeries in 2020. Federer made his comeback last year but played only five events before deciding to undergo another knee surgery. Federer was 39 and coming off two knee surgeries when he made the Wimbledon quarterfinal last year. Federer, who underwent a third knee surgery last August, could make his comeback in the second part of this season. “I can’t comment on Roger Federer, I don’t know.As he said in his congratulatory message to Rafa, a great champion should not be underestimated, they are capable of coming back, Federer achieved that feat well in 2017 in Australia,” Rosset told RTS, according to Tennis Up To Da …