SAM Allardyce hopes that the injury sustained to Ryan Nelsen isn't a serious one.

The New Zealand international landed heavily after challenging for the ball in the first half of Rovers' 3-0 win over Bolton Wanderers at Ewood Park.

The Rovers captain returned to action briefly after receiving treatment but was unable to continue and was replaced just before the break.

"Having only looked at it on the replay I'm hoping that he's twisted his ankle and not his knee," said Allardyce immediately after the game.

"But he was holding its knee which was the big problem for me.

"I think it is his one where he's had surgery before, so it'll be 48 hours before we can tell and we'll keep our fingers crossed, not just for us but for him."