Guinness Premiership leaders Bristol have suffered a major blow with the loss of their former England hooker Mark Regan for up to six weeks.
Regan, who played pivotal roles in the opening league wins against Bath and Newcastle, broke his thumb during the Newcastle Falcons clash and has undergone surgery.
"Mark has had it operated on and the surgery went well, so we are looking at maybe six weeks for him, aiming at the European games against Narbonne and Northampton (in late October)," said Bristol physiotherapist Paul Tompkins.
"It is a blow, and he is understandably gutted with the team going so well."
Regan, a member of England's World Cup-winning squad, is set to miss Premiership appointments with Gloucester, London Irish and Saracens, plus Powergen Cup clashes against Bath and Gloucester.
Josh Strauss has a Scotland call-up in the back of his mind but the Glasgow Warriors back-row admits he must build on an impressive first two seasons in the country to catch Vern Cotter's attention in time for the World Cup.