Update: On Monday this week, following Novak Djokovic's lopsided win over Tommy Robredo, Novak said this in the press conf.:
“I hope he [Federer] recovers fast, because we are not used to seeing him injured. He’s very fit, and he plays very well throughout the entire year,â€
Well, maybe Roger heard Novak and wanted to reassure him, because on his twitter the next day, Roger posted:
Trying to be man. Back at it!
That's Federer's expert fitness trainer, Pierre Paganini receiving.
Two hours later, Roger posted:
Rarely felt so happy being back on a practice court
Oh, what a web Spiderer weaves...
Encouraging that Roger is back to training already after the knee surgery.
Shout out to Baron @britbox to update the thread title... 
Respectfully,
masterclass