United boss Sir Alex Ferguson has responded to intense speculation over Rooney's future by insisting the England striker will still be at Old Trafford next season.
But Mancini was still asked whether he might be tempted to test United's resolve over the 27-year-old.
Roberto Mancini: "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).
"I don't know. I don't know this situation.
"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."