Manchester United v Manchester City: Weaker teams try harder in games with us than they do against United, says Roberto Mancini

City manager’s latest excuse for title race gap is that Ferguson’s side frighten other teams

Roberto Mancini, the Manchester City manager, is frustrated by the “poor mentality” of many Premier League sides whose fear of facing Manchester United has allowed Sir Alex Ferguson’s side to establish a 15-point lead in the Premier League.

The Italian, who argued that City would be “100 per cent” in the title race and have reached the Champions League quarter-finals had he got all the players that he asked for in last summer’s transfer market, claimed those sides whom United had swept aside were a different proposition when his club encountered them.

“No one plays well against United because they only play with fear,” he said, ahead of tonight’s derby at Old Trafford. “I don’t think [other teams] play 100 per cent [against United]. Their mentality is poor in that game. They think they can do nothing but instead I don’t think that is true. If you play with mentality, in football you can beat every team.”

Mancini, who spent three days in Abu Dhabi last week, faces a defining week in his City tenure, with tonight’s match and Sunday’s FA Cup semi-final with Chelsea providing evidence of whether the club are actually developing under his leadership.

Though the club’s new ex-Barcelona management – their chief executive, Ferran Soriano, and their director of football, Txiki Begiristain, – want to foster the philosophy of organic development they have brought from Catalonia, Mancini still sees the transfer market as the key to reclaiming the title United are almost certain to clinch.

“I don’t know [how many we will sign]. It is difficult to say,” said Mancini who missed out on Robin van Persie, Eden Hazard, Daniele de Rossi and Javi Martinez last summer. “You want one player, maybe two or three teams want the same player and after you can take this or take another player. After, it is difficult.”

Having cited the loss of Mario Balotelli as one of the reasons why City have scored 20 goals too few, Mancini said that the club’s failure to reach the latter stages of either the Champions League or Europa League damaged his hopes of signing a top striker in January. “Without international competition, it was better we left it for the summer,” he said, his tone more diplomatic towards Begiristain than Brian Marwood, the former de facto football director.

City must sell to buy, with Joleon Lescott, Aleksandar Kolarov, Scott Sinclair and Maicon likely to leave and Samir Nasri’s future uncertain, though Barcelona’s interest in their captain Vincent Kompany presents a challenge. The Belgian, one of the bedrocks of the side, signed a six-year contract last year but that may not deter Barça. City face competition from Real Madrid in their pursuit of Napoli’s Edinson Cavani, who has a £52 million release clause.

Mancini said that second place and an FA Cup would represent a good season. “Yeah. I think maybe you can’t win every year,” he said. “Last year United didn’t win anything – only the Charity Shield – but they continued to improve their team. This can happen. You can’t win every year. This is impossible in England. For this, I think we need to do better next year.”

Last season’s 6-1 win was not a direct motivation, he added. “We can go there and think that ‘Okay we beat them 6-1 and this will be the same’ but every game will be difficult,” he said. “The game we played at Etihad Stadium [in December and lost 3-2], we deserved to win. Like United, we are a strong team. There is no difference. We have been missing important goals in games we deserves to win easily like West Ham, Chelsea away, Sunderland, Arsenal at home. We lost a lot of points because we didn’t score enough goals. This is the difference. Probably we have not played like last year. Sometimes we played very well, sometimes only so-so.”

Ferguson, who said he expects to have Wayne Rooney back from the groin strain he suffered on England duty, repeated his declaration that his investment in youth will enable United to deal with City’s threat, even though he expects them to out-spend him this summer.