Manchester United manager Alex Ferguson says captain Nemanja Vidic's calf injury is worse than first thought with the defender now facing up to five weeks on the sidelines.
Vidic was hurt in Sunday's 2-1 win at West Bromwich Albion, but Ferguson initially expected him to be out for just two weeks.
But Ferguson said Friday that "the situation has reversed and Vidic has a calf muscle injury, which means he'll maybe be four to five weeks."
Vidic will miss Serbia's European Championship qualifiers at Northern Ireland on Sept. 2 and against the Faeroe Islands four days later.
There was better injury news for United, with Rio Ferdinand now potentially returning from a hamstring injury for the Aug. 28 match against Arsenal.