Boss Alan Pardew told the club website: "He's in the autumn or winter part of his career now where he doesn't need injuries of this type.
"I feel for Murts because he is an important player. We've not had him all year so that hasn't really worked out."
Murty, who also suffered a knee injury in August, has made just nine appearances for Southampton since joining them on a free transfer from Reading last summer.
Pardew added: "Graeme and myself know each other very well and we might have to look at each other at the end of the season and see where we are going to go from there."
The manager is more hopeful on striker David Connolly's prospects as he continues his recovery from injury.
"He has made progress, which is good," he said.
"We don't think it will be this week but maybe the week after, which is good news because we have missed his goals, particularly that second goal away from home."
Source: BBC Sport
Source: BBC Sport