Connacht have announced that full-back Tiernan O'Halloran has suffered a hamstring injury during their 26-15 win over Ospreys.
The province's medical team say he is due to be out for a number of weeks.
The injury will be a blow to any hopes O'Halloran had of appearing in this year's Six Nations but also leaves the full-back in a race to be fit for Connacht's Challenge Cup quarter-final against Gloucester.
Connacht will welcome the English side to the Sportsground on March 31.
The game with Ospreys also resulted in the loss of Andrew Browne, with the second-row picking up a shoulder injury ruling him out for 4-6 weeks.
There was good news for the Westerners, however, as winger Niyi Adeolokun and back-row Jarrad Butler returned to training this week.