Titus Bramble believes that Sunderland boss Paolo Di Canio has "a lot to learn" about management.
The defender will leave the Black Cats at the end of the month after being told that his contract will not be renewed.
Bramble told The Telegraph: "I've never played under anyone like him and I've played for some of the best managers around. Steve Bruce, Roberto Martinez and Sir Bobby Robson. He thinks he knows everything, but he has got a lot to learn.
"He's a young manager trying to stamp his mark on things, but he's making some big mistakes. He's targeted the easy players, the ones who are leaving anyway, trying to show he's the boss.
"I was fined for not going to a weights session. Everyone else at the club thought it was ridiculous, but he's trying to be tough."
Bramble made 51 appearances for Sunderland during his three years at the club.
