Newport and Wales centre Andy Marinos has damaged ankle ligaments and will be out for 10 weeks, ruling him out of the Black and Ambers final Heineken Cup match against Edinburgh.
Newport's options are further limited by Jason Jones-Hughes' continuing injury problems, but the club hope that Hal Luscombe and Luke Nabaro, who missed the Toulouse game, will be fit for Edinburgh.
Neither side has a chance of progressing to the quarter-finals, but will be looking for consolation victories to end hugely disappointing European campaigns.
The injury is a double blow for Welsh rugby, following hot on the heels of the injuries to Pontypridd duo Sonny Parker (broken arm) and Jon Bryant (hamstring) that will also keep them out of Steve Hansen's Six Nations squad.