The Argentina striker has scored four goals in his last three games and Kompany reckons he is ready to pile misery on his old club.
"Carlos has done what everyone knew he was capable of which is scoring goals," said Kompany. "His passion on the pitch has been great.
"I can say one thing about Carlos - the great thing about him is that he approaches every single game like it's the most important of his life.
"He did it against Wolves, he did it against Norwich and he'll do it against United.
"He's a guaranteed performer, that's what you get from him.
"But I'll be very surprised if there is any player not up to the same level of motivation."