Warren, who was the stand-in captain for Inverness in the absence of Richie Foran, was on the receiving end of a hefty challenge from Stephen Pearson and was carried off the pitch before the break.
Caley John Hughes confirmed after the match that Warren had been taken to hospital in an ambulance and is keeping his fingers crossed that the 30-year-old has not suffered a broken leg.
As well as Warren’s injury, Foran and Aaron Doran missed out on the matchday squad while Josh Meekings was taken off at half-time.
“It’s massive. Gary is our captain and we’re hoping he’ll be alright. If there’s no crack or break then he’ll play next week,” said Hughes.
“I couldn’t tell you what Josh’s injury was – I haven’t spoken to him. He came off and went straight into the physio’s room.
“Everything went for us last year but injuries are creeping up. We can’t feel sorry for ourselves. It’s part and parcel of football.”