Former Sunderland midfielder Kevin Kilbane feels Paolo di Canio fell out with his players.
Di Canio was sacked by Sunderland yesterday.
Kilbane said: "It was a huge gamble to give Di Canio the job in the first place. The gamble was that there were seven games to go and they needed to stay in the Premier League.
"They wanted an impact and he managed to keep them up last season. But it was a short-term appointment, not a long-term one.
"Di Canio questioned the players' diet, their desire and their heart. He questioned them as players and as people, so it's no surprise if they are unhappy."