"Once (Kerber) beat Serena, everybody thought, Oh, we have a chance," says Hall of Famer.
World No. 1 says while Monfils' judgement was "unacceptable" he is an asset to tennis.
After McEnroe calls Monfils "borderline unprofessional", US Open semifinalist answers.
Top seed uses forehand flick to create amazing angle.
Keep up with all the action from the men's semifinals at the U.S. Open with the Tennis Now Live Blog!
Avenging Cincinnati final loss to Pliskova requires more aggression says second seed.
No. 10 seed explains why Venus presented a tougher test than Serena.