Ireland and Leinster prop Cian Healy is expected to be out for three to four weeks following a procedure on his knee.
The 28-year-old's injury will leave him with little time to be fit for the start of the Six Nations in February.
Healy was given a two-week suspension on December 31 for striking Toulon hooker Guilhem Guirado in the two sides' Champions Cup meeting earlier that month.
He was previously expected to be fit in time for Leinster's Champions Cup clashes with either Bath on January 16 or Wasps on January 23, but will now miss both games.
Ireland head coach Joe Schmidt will be hoping that the experienced prop recovers in time to be ready for Ireland's Six Nations opener at home to Wales on February 7.