Manchester United have announced that striker Robin van Persie will be out of action for around four to six weeks with a sprained knee.

Manager David Moyes revealed on Friday that the Dutchman was due to undergo more scans, but had been ruled out of Saturday's clash against West Ham United.

Van Persie picked up the injury after scoring a hat-trick against Olympiacos to push the Red Devils through to the Champions League quarter-finals on Wednesday.

Despite being stretchered off in the second half at Old Trafford, there were suggestions that Van Persie could return for Tuesday's Manchester derby.

However, the club have now confirmed on their official Twitter account that, after "further investigation", Van Persie is unlikely to return to action before the end of April.

The 30-year-old will be absent from United's Premier League clash against Manchester City, as well as the Red Devils' first and second legs against Bayern Munich in the quarter-finals of the Champions League.