On-loan West Ham striker Andy Carroll is expected to be out for up to eight weeks with a knee injury.

The England forward, who is on a season-long loan from Liverpool, was hurt in the midweek defeat against Manchester United and replaced by Carlton Cole after 62 minutes.

Hammers manager Sam Allardyce said: "It's pretty severe. We didn't expect it to be quite as severe.

"It's going to be about six to eight weeks. It's a blow for us and Andy."

Carroll, who has scored one goal in ten appearances for West Ham this season, has already missed one month of the campaign after suffering a hamstring injury against Fulham in September.

But Allardyce said Carroll would not be returning to his parent club for treatment: "Andy will be staying with us.

"We have contacted Liverpool, they have all the information, they sent a representative down to assess him, but they use the same specialist as we do, which helps and hopefully he can now recover as quickly as possible.

"We must soldier on. The lads out there have plenty of experience but we are a bit light on the bench."