Rhys Ruddock will be out of action until mid-January after fracturing his arm against Harlequins on Saturday.
“Rhys broke his arm,” revealed Leinster team manager Guy Easterby.
“It looks like he will be out for about four to six weeks. There are bumps and bruises around the camp but nothing else significant and anyone who is sore from the weekend should be available.”
The injury rules Ruddock out of the interprovincial PRO12 games in the coming weeks and leaves the back row with just a slim chance of lining out for Leinster in the European Champions Cup rounds five and six games against Castres and Wasps.
Ruddock will likely be returning just in time for Ireland’s opening 6 Nations game against Italy in early February.