The Blues central defender went down under a challenge just minutes before the half time whistle with what looked like a bad ankle injury and was replaced by youngster Duane Courtney.
Tests will show whether or not Purse has ligament damage.
Midfielder Aliou Cisse also got a knock during the 1-0 defeat to the Reds at Damson Park and was substituted with 15 minutes remaining, although his injury seemed far less severe.For Reserves Match Report Click Here