Bristol captain Dwayne Peel's return to first team action has been deferred until March.
The Wales and British and Irish Lions scrum-half has not featured in a competitive fixture during the 2015-16 season.
Explaining Peel's continued absence, the official Bristol website said: "The extended period is to resolve a minor issue arising from shoulder surgery undertaken during the early part of the campaign."
Former Scarlets product Peel, 34, joined Bristol in 2014 after spending six seasons at Sale Sharks, where he made over 120 appearances.
Bristol have opened up a seven-point lead at the top of the Greene King IPA Championship in Peel's absence as they chase promotion to the Aviva Premiership.