Sherwood told The Sun: "As a player you should want to get on and prove people wrong.
"It's all been a bed of roses since Berbatov came to White Hart Lane, he is so talented he could play for any club in the world. Last season, he produced flashes of brilliance that reminded me of Dennis Bergkamp the way he stroked the ball and the passes he made.
"If I was Alex Ferguson and Manchester United, I'd be looking at him now to see how he reacts when the team is struggling.
"It's absolutely brilliant when players are flying high and nice things are being written about you. But that kind of attitude gets the manager the sack.
"He is a big character in the dressing room and if he starts poisoning the rest of the boys you have had it. You need players in the trenches in this situation, players who are going to fight for you."