Troubled striker Mario Balotelli is at war with himself, according to Manchester City team-mate Yaya Toure.
The Italian was hauled off by Roberto Mancini during the second half of Sunday's 3-2 derby defeat by United.
It was the latest disappointment for Balotelli, 22, in a season that promised so much after his Euro 2012 performances with Italy, the Daily Star reports.
"Mario is an unbelievable player, but sometimes he can be angry with himself. All players need to improve and I talk all the time with Mario," Toure said.
"This year especially he has been working hard in training and improving well - but sometimes in the game you can get so disappointed when you lose small things," he added.
"But he has fantastic character and I know he will be one of the top strikers in the Premier League," he continued. (ANI)