Every so often, a debate bubbles up around whether it makes sense for men to keep playing best-of-five-set matches at Wimbledon and other Grand Slam tournaments.

And Roger Federer is hailing the Serb’s comeback as “amazing.” “Novak’s amazing, how he’s bounced back,” Federer said in an interview with ESPN’s Chris McKendry before Djokovic beat Alexei Popyrin, 4-6, 6-3, 6-4, 7-6 (3) to advance to a showdown with No. 15 Holger Rune.

Alexei Popyrin (No. 47 ranking) will meet Novak Djokovic (No. 2) in the Round of 32 of Wimbledon on Saturday, July 6.Djokovic is favored (-1000) against Popyrin (+450) in this Round of 32