Pablo Zabaleta has indicated that Manchester United 's seven-point lead over Manchester City means Roberto Mancini 's men cannot afford any more slip-ups.
The reigning Premier League champions did not have the best of months in December, dropping points by drawing with Everton, losing 3-2 in the Manchester derby and suffering a shock defeat to Sunderland on Boxing Day.
Despite a convincing win at home to Stoke City on New Year's Day, the Blues are seven points behind Sir Alex Ferguson's men. The 27-year-old was happy with the victory but is wary that the team are under a lot of pressure to keep producing.