A club statement on the 29-year-old reads: “Results have shown that Cullen has suffered a multi-ligament injury, including a ruptured ACL.
“The injury will be reviewed by the surgeon later this week, but Mark will likely require surgery which will keep him out of action for a lengthy period.
The club's head of medical Gareth Thomas said: “It’s very unfortunate for Mark, having only just arrived at the club. It’s never nice to see a player leave on a stretcher but he’s in good spirits and is in a positive mood.
“He will most likely require surgery, which will keep him out of action long-term.”
It means James Rowe goes into his first match as Coasters manager away to Kidderminster Harriers tomorrow without the target man.
The clubs stand third and fourth in National League North, with the Harriers three points better off with a game in hand.
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