The Red Devils currently hold a 12-point lead over City at the top of the table and, despite the reigning champions' thrilling comeback to win last season, the German thinks the title is "decided" for the 2012-13 campaign.
"With the defeat against Southampton and United's victory against Everton, the championship is decided," Rosler told Goal.com. "But [qualification for] the Champions League is not in danger."
The Citizens also failed in the Champions League this season, finishing bottom of their group and, while Rosler insists the players are good enough, he does not believe enough experience runs through the club at the very highest level.
"To be honest, the Champions League was a disappointment. The players and coach have sufficient experience, but not the club," Rosler said. "The group was very hard. But it's quite disappointing they didn't even manage to reach the Europa League."
Speculation over manager Roberto Mancini's future at the club continues to be a hot-button issue, with Michael Laudrup reportedly one of a small number of managers already being lined up to replace the Italian in the eventuality that he is sacked.
Rosler has been mentioned as a dark horse for the role at the Etihad Stadium, but insists he is not entertaining thoughts of a return to his former club.
"For the moment, it's unrealistic," Rosler said. "Just the best three or four managers in the world will be candidates for coaching City. That's still a long way for me."