Motherwell midfielder Keith Lasley will not play again for rest of the season due to a cruciate ligament injury suffered on Saturday in Inverness.
Lasley was hurt in the victory at the Caledonian Stadium
He was stretchered off in the 1-0 win at The Caledonian Stadium following a challenge with Ian Black.
"It's a real body blow," said manager Maurice Malpas. "Keith has been excellent for us."
Lasley re-joined Motherwell in the summer after leaving Fir Park for a two-year stint with Plymouth.
"It's a big blow for him first of all and it's also a blow for the club," added Malpas.
"He is one of our more experienced players and had formed an excellent partnership with Brian Kerr in the middle of the park.
"He will be a big loss to us."
"It's a possibility that we might need to bring someone in and it also looks as though we will have to change our thinking in terms of what our priorities are now."
Malpas is now likely to search for Lasley's replacement when the transfer window opens in January.