Livingston face around three months without Adam Lewis after the on-loan Liverpool player broke his foot.
The versatile 21-year-old suffered the injury during training on Monday with nobody else near him.
Manager David Martindale said: “Adam has returned to Liverpool and is probably going to be 12 weeks, he broke his fifth metatarsal.
“We were doing a recovery session, playing small-sided games, no contact, he went to take a shot with his left foot and slightly rolled his foot.
“They took him down to Liverpool and are going to pin it, so that’s probably a 12-week injury.”
Lewis has made eight appearances for Livi after overcoming a fitness issue earlier in the season.
“I feel for Adam because I think he was hitting a bit of form,” said Martindale, whose team host St Mirren on Saturday.
“He was getting there, he was understanding and adapting to the Scottish game. So I’m gutted for the kid.
“There’s a big pressure coming from Liverpool. These loan players are coming up to Scotland and they really need to play if they have any future at their parent club.
“So they come up and sometimes they get a shock at the standard and intensity of Scottish football.
“You just need to look at the players that have left Scottish football of late and see how they are doing in the Premier League, big (Kristoffer) Ajer is doing brilliantly down there and (Odsonne) Edouard comes on and scores two goals on his debut.
“I think Scottish football gets a raw deal, especially outside the Old Firm, and these players come up and get a wee bit of a shock to the system, with the intensity, aggressiveness and physicality but also the ability levels.
“But they are coming up to impress their parent club, which is the most frustrating thing for young Adam, because I genuinely feel he was there or thereabouts.”