Manchester City v Manchester United: United threw away the title last season, says Roberto Mancini "They thought it was over," the City manager said bluntly of why United stuttered, losing two and drawing one as Mancini's side won all their final half-dozen matches to claw back the lead and claim the title on goal difference on the final day of the season. "I think the second derby here we played very well, we didn't concede any chances," Mancini said. I think it was a truer reflection on how well we played. Ferguson has conceded that he was probably too "cautious" in the game last April and said he regretted playing Ji-Sung Park ahead of the more attacking Danny Welbeck. But he said Robin Van Persie, who chose United ahead of City last summer, could make a crucial difference on Sunday afternoon. Ferguson said that the former Arsenal striker, signed for £24million, was the reason why United had managed to mount so many comebacks this season - they have recovered an incredible 18 points from losing positions. "I think it's down to Van Persie to be honest, the threat he has given us up front," he said. Van Persie has been really brilliant for us. He's relished coming here.