Darlington's on loan defender Evan Horwood is out of action for at least a month after fracturing a bone against Barnet.
The club had hoped Horwood, who is on loan from Sheffield United, had only suffered a dead leg in last weekend's 2-0 success over The Bees, however, scans have proved otherwise.
On Monday the youngster was diagnosed with a hairline crack of the fibula, meaning at least a month on the sidelines recovering.
"What looked to be a straightforward dead leg has unfortunately turned out to be a cracked fibula," physio Paul Gough told the club's official website.
"I did have a suspicion after the game and I did say to him it was similar to the injury that Sam Russell had. That appeared to be a straightforward kick to the leg.
"The position it is in, there is no protection there, no muscle and it makes it highly likely to crack.
"I spoke to him on Saturday night and again on Sunday and he was struggling to walk and couldn't put any weight on it."