Stevenage forward Ben Kennedy is out for the rest of the season after injuring his knee in a training session with the League Two club.
The Northern Ireland Under-19 captain, who signed a three-year contract in October, is set to undergo surgery.
"This is yet another blow for the club and for Ben personally," chairman Phil Wallace told the club website.
"I've never seen an injury crisis like this and I can't believe it's got worse."
Stevenage are 19th in the table, having failed to win any of their last five matches, but boss Teddy Sheringham has been cleared to seek reinforcements for his squad.
"Combined with various loan deals expiring, it does leave the squad particularly thin," added Wallace.
"However with the transfer window now open we're working day and night to get the right players in so we can climb the table."