Norwich City striker Aaron Wilbraham is likely to miss the rest of the season after undergoing surgery on a disc in his back.
The 31-year-old has not featured since his goal-scoring appearance in the 3-2 win over Leicester on 8 March.
Since joining from MK Dons on New Year's Day he has made six starts and seven substitute appearances.
"Losing Aaron has possibly been the biggest blow we've had," boss Paul Lambert told BBC Radio Norfolk.
"Losing Aaron is a major blow because, if you're going to compare him and Grant Holt, he's maybe the only one who can do what Grant does.
"I think Aaron took a bit of weight off Grant and I thought he was playing very well.
"Playing with the back problem he showed you he wanted to do it, he'd run through a wall for you."
Meanwhile Zak Whitbread and Henri Lansbury have returned from injury.
Defender Whitbread was recalled from the USA squad ahead of last week's internationals with a back problem.
While on-loan Arsenal midfielder Lansbury was withdrawn from the England Under-21s because of a slight knock.
The blow of Wilbraham's absence will be somewhat eased by Norwich's signings of front pair Sam Vokes and Dani Pacheco from Wolves and Liverpool respectively last week.