Swiss tennis ace Roger Federer conceded after his French Open third-round win that he would prefer to be in world No. 1 Novak Djokovic or world No. 3 Rafael Nadal's shoes right now where they are playing really well and winning their matches. The 39-year-old former World No. 1's last Grand Slam title came at the Australian Open in 2018. He has since battled injuries, undergoing two knee surgeries, which laid him low for almost all of 2020. Federer also withdrew from the 2021 Australian Open as he was still recovering from the two surgeries on his right knee. On Saturday, the No. 8 seed came back strongly in his third-round match against an opponent 12 years younger, Germany's Dominik Koepfer, to secure a pre-quarterfinal spot at Roland Garros. "It's fun in some ways not knowing, like in '17 when I came back or when nobody really knows, even (I don't) know what is possible. That's got a fun angle, but I would prefer it differently. I'd prefer to be in Rafa's or Novak's shoes right now where they're like, 'I'm feeling good. If I'm playing well, I'm winning'," said Federer, referring to the 2017 season where he returned from a back injury and a knee surgery to win two Grand Slam titles -- the Australian Open and Wimbledon. With Federer again on a similar mission following the knee procedures in 2020, the winner of 20 Grand Slam titles said: "I don't have that (2017) feeling right now, so for me these are all stepping stones to something that is really important to me. It's the season, and it's the comeback. I need (tough) matches like these." Federer's match against Dominik Koepfer lasted three hours and 39 minutes. "I thought it was very important for me (to win against Koepfer). I didn't expect to be able to win three matches here. So I'm very happy. For me to go out tonight, sure, it wasn't easy. It was a lot of [firsts] for me: Playing against Koepfer (in my) first night session here in Paris, first time [with] no fans in a long, long time, or ever in my career. That was definitely very unique in many ways, and I'm happy I found a way," Federer told atptour.com.