West Brom striker Shane Long could face up to six weeks on the sidelines after a scan confirmed the extent of the knee injury he suffered against Aston Villa on Saturday.
Long was forced to leave the field in the 19th minute after a challenge from Villa defender Alan Hutton eight minutes earlier.
The force of the tackle resulted in the Republic of Ireland international suffering severe bone bruising and a small bone chip, inside his right knee.
The news means Long is unlikely to be fit for the Republic of Ireland's Euro 2012 play-off games with Estonia on November 11 and 15.
Speaking after Saturday's game, which his side won 2-1, West Brom boss Roy Hodgson felt there was "no room in football" for the type of challenge from Hutton.
Hodgson said: "I don't think it will be good news when the scan comes through because it was such a vicious challenge.
"I suppose he has got to consider himself lucky he hasn't got two broken bones in his leg but I would think it is a serious knee injury.
"I was disappointed with that challenge by Hutton and not only saddened by it, but angered by it.
"I don't think there is any room in football for those type of challenges on the field and overall the game wasn't like that."