Larsson missed the weekend's defeat to Arsenal as a result and the report now reveals he will miss the busy festive period which sees the Black Cats play Watford, Chelsea, Manchester City and Liverpool before the year concludes - and could be sidelined for a potentially crucial home fixture against Aston Villa at the start of 2016.
The Sweden international has been having trouble with his knee for some time so manager Sam Allardyce will no doubt be happy that the problem is being sorted, but it is something of a blow to lose one of his midfield options ahead of a busy fixture schedule.
Fellow midfielder Lee Cattermole has suffered a recurrence of a back injury and there has yet to be a timescale put on the injury, even after visiting a specialist in the most recent international break about the problem.
It would be best for the Sunderland boss to get a timescale on the injury to Cattermole as quickly as possible. Though he may not be the most pleasing player on the eye he has certainly been effective for Sunderland for many years, as he has provided that edge in midfield that opposition sides don't tend to like.
As for Larsson, Allardyce will look to other areas of the side to provide that creativity that Larsson has done for some time. Given that there has been something of a resurgence in their form lately, Sunderland will probably feel they can cope with these losses during this busy period, and come through these games with a good points return.