The England international’s Red Devils future has been a source of constant speculation in recent days after Sir Alex Ferguson left Rooney out of his starting line-up for their 2-1 loss to Real Madrid.
The 27-year-old was linked with a move to the Citizens during a breakdown in contract talks between Rooney and United in 2010 before the striker eventually decided to pen a long-term deal at Old Trafford.
“I think that Rooney is one of the best strikers in Europe but I think it is difficult he can leave Man Utd – I don’t think [so],” he said.
Earlier on Friday, Ferguson insisted that Rooney would still be at United next season – and Mancini doubts that being dropped for one game would prompt the former Everton forward to seek a move away from Old Trafford.
“I don’t know. I don’t know this situation,” he added.
“I can understand maybe Rooney would be upset if he didn’t play but these are things that can happen in every team. After one week it is finished.”
Mancini also confirmed that captain Vincent Kompany and striker Sergio Aguero will not be available for City’s FA Cup quarter-final against Barnsley on Saturday.
“I don’t think it is serious but in this moment we can’t take a risk with Sergio,” he said.
“Vinnie was training with the team yesterday but I don’t think we can risk Vinnie. Maybe he is ready for the next game against Everton.”