Wales and Ospreys flanker Justin Tipuric could miss the rest of the Guinness PRO12 season as he continues his recovery from concussion.
The British & Irish Lions star suffered the injury in a heavy lineout fall during Wales' closing RBS 6 Nations victory over Italy in Cardiff.
Ospreys backs coach Gruff Rees told the BBC: "We're not even putting any thought process around when the next game for Justin can be.
"It may be we just sit tight and see the season out and get to the June. He was in the office last Friday and he had a tough old week of it in terms of just being inactive at home and really not being comfortable getting out and about.
"And we're not putting any pressure on him having to do anything but sitting on the sofa. You've got to be really wary and sit back and look at the long-term betterment of these players."