WEST Ham midfielder Jack Collison has been ruled out for up to seven weeks with a dislocated kneecap.

After undergoing an arthroscopy on the injury the Welshman picked up during the 1-0 win over Wigan Athletic, it was revealed he had not damaged any ligaments in his knee, but the 20-year-old will still miss the majority of the season.

However, he may still be back for the final few games, which could prove crucial for the team's pursuit of a Uefa Cup place.

The news follows confirmation that winger Valon Behrami will be kept on the sidelines for six months after damaging his anterior cruciate ligaments in his left knee against Manchester City two weeks ago.