The seven-time champion has lost just one set in four rounds, but that was a mere blip on a tie-break during an otherwise controlled victory over Australian Sam Groth, and the 33-year-old has yet to drop his serve.
The latter factor shows Federer is sending down the ball as well as ever. However, he expects Frenchman Gilles Simon to return better than anyone he has tackled, and accepts that may mean his serve takes some punishment.
“Gilles Simon is one of the best return players we have in the game. I would think I’ll be tested a lot,” Federer said. “That streak is maybe coming to an end, in my opinion.”
Federer joked that his opponents until now have been “returning terrible”.
In their previous grand slam matches at the 2011 Australian Open and 2013 French Open, Federer has been taken to five sets both times by Simon, a 30-year-old born in Nice but resident in his opponent’s native Switzerland.
Their match is first on Court One, ahead of another clash of players from Switzerland and France as Stan Wawrinka takes on Richard Gasquet.
Andy Murray opens up Centre Court proceedings against surprise quarter-finalist Vasek Pospisil, with Novak Djokovic then playing Marin Cilic and looking to augment a 12-0 career head-to-head record against the Croatian.