Hartlepool United will be without Colin Larkin for up to three months as the striker needs a second operation on a knee problem.
The 29-year-old initially had surgery in April and saw a specialist in London on Wednesday, who advised further work to clear up the issue.
"It's tough on Colin," boss Neale Cooper told the club website.
"We need to get to the root of the problem and hopefully this latest operation will help us do that."
Larkin has scored four goals in 63 appearances for the club following his switch from Northampton Town in August 2009.
However injury has limited the former Wolves forward to only three appearances in 2011-12, the last of which came in the club's 2-0 Johnstone's Paint Trophy defeat by Scuntorpe in August.
Meanwhile fellow centre forward Colin Nish is back in training after he completed rehabilitation following a knee cartilage problem.
"We can't rush him too much so we'll just gradually build him up in training," Cooper continued.
"It's important that he doesn't try to do too much too soon but the medical staff have been brilliant with him.
"Hopefully we can get him back involved in a reserve game in the coming weeks."