Sherwood told The Sun: "As a player you should want to get on and prove people wrong.
"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."