Ulster scrum-half Ruan Pienaar will miss the province's final Champions Cup pool games after undergoing minor knee surgery.

The Springbok injured his knee in Ulster's New Year's Eve Pro12 derby defeat to Leinster. He completed the full 80 minutes but has now been forced to have surgery.

The 32-year-old will miss Friday's Pro12 trip to Scarlets and the crucial Champions Cup games away to Exeter and at home to Bordeaux.

He is expected back for the league meeting with Edinburgh on February 10.

Ulster face an uphill battle to make the last eight of the European competition; they lie third in Pool 5 with nine points from four games.

Pienaar will end his six-year stay with the northerners at the end of the season after the IRFU refused to allow Ulster to extend his contract due to their succession policy for developing indigenous talent.