Watford defender Martin Taylor will be out for up to three months as he recovers from a dislocated collar bone.
The 31-year-old underwent surgery last week for the injury he picked up in a collision during the club's defeat by Crystal Palace three weeks ago.
He had played in every league game this season up until that point.
"He has had a reconstruction of the joint between his shoulder blade and collarbone," Hornets head of physio Dave Hart told the club website.
"Once he's completed his rehabilitation, there's no cause for concern around that area as there might be with, say, a shoulder dislocation for example.
"Typically, providing the surgery has gone well, which we think it has, we'd be looking at getting him back in the region of around three months."
Meanwhile, defender Lloyd Doyley (thigh strain) and midfielder John Eustace (back) are expected to return within the next two weeks.