Murphy blow for Boro
By Peter O`Rourke
Last Updated: 01/01/70 1:00am
Murphy, who was making his first Premiership start at St Mary's, sustained the injury 15 minutes into the game and was forced to be replaced by Colin Cooper.
The 18-year-old left the ground on crutches and tests have shown he has sustained damaged ligaments.
The highly-rated full back is now set to be out of action for four to six weeks and is a blow to Boro boss Steve McClaren with Franck Queudrue still suspended.
Cooper is set to keep his place in the side when Boro entertain Fulham next weekend.