Arsenal's hopes for next week's Champions League second leg with Barcelona have suffered a blow after striker Robin van Persie was ruled out here Tuesday, the club said.
Dutch striker van Persie, who scored in Arsenal's 2-1 win over Barcelona in the first leg, suffered a knee injury while scoring for the Gunners in the League Cup final against Birmingham at the weekend.
Manager Arsene Wenger told Arsenal TV Online that van Persie would be out for at least three weeks.
"Unfortunately, we had bad news on the scan and he will be out for the next three weeks for sure," said Wenger.
"It could be longer. The shortest delay we can imagine is three weeks [so] he is definitely out for Barcelona."
Van Persie's injury could not have come at a worse time for the Gunners as they seek to overcome the bitter disappointment of Sunday's League Cup defeat to Birmingham at Wembley.
Arsenal play Leyton Orient in an FA Cup fifth round replay on Wednesday, and will face Manchester United in the quarter-finals should they progress.
The trip to Old Trafford falls on the weekend after the Barcelona tie at the Nou Camp next week.