West Ham's Ricardo Vaz Te will be out of action for three months as he recovers from shoulder surgery.
Vaz Te, 26, dislocated his shoulder as he collided with Vito Mannone in West Ham's 3-1 Premier League defeat to Arsenal on October 6.
Keyhole surgery was decided as the best treatment for the former Bolton man, who underwent the operation on Monday night.
A statement from the Hammers read: "West Ham United can confirm that Ricardo Vaz Te underwent successful shoulder surgery on Monday evening as he continues his recovery from the dislocation he suffered during the Barclays Premier League fixture against Arsenal on 6 October.
"Head of Sports Medicine Andy Rolls and his medical team have been working with Vaz Te since the match to determine the right course of treatment and it was decided that keyhole surgery was the best long-term solution to ensure there were no further complications.
"After being kept in hospital overnight for observation, Vaz Te will now start his rehabilitation, which is expected to take up to 12 weeks."
West Ham manager Sam Allardyce believes Vaz Te's absence will give a chance for other players in his squad to step forward and stake a claim for a place in the starting line-up.
"We've got some good players ready to step up in place. Matt Taylor has been there and there are others in the squad that haven't quite played as much such as Gary O'Neil,'' he told the club's official website.
"Whichever option we pick it's up to them to step up to the mark. They need to provide the attacking opportunities that we need.''
Information from the Press Association was used in this report