Manchester City defender Martin Demichelis will be out for around six weeks after it was revealed that he had suffered knee ligament damage in training.
The 32 year old Argentine centre back was signed last weekend from Athletico Madrid to cover for injured defenders Vincent Kompany and Micah Richards.
His subsequent injury means he will miss Premier League matches against Stoke City, Manchester United, Aston Villa and Everton, plus Champions League ties against Viktoria Plzen and Bayern Munich.
Kompany was hopeful of returning for the game against Manchester United but City manager Manuel Pellegrini may be reluctant to risk another injury to their captain.
City have just two fit central defenders, Joleon Lescott and Matija Nastasic, both left-footers, and may have to draft youngster Dedryck Boyata into match day squads for both the Barclays Premier League and the Champions League or consider deploying the likes of Javi Garcia or Yaya Toure into defence.