Star signing Charles Piutau will miss Bristol's English Premiership opener against Bath on Friday after suffering a shoulder injury in a pre-season friendly.
The former All Black, a reported £1 million ($1.3 million) arrival from Ulster, is due to see a specialist this weekend after the incident in a match against Connacht.
The New Zealand fullback's absence is a major blow for Bristol on their return to top-flight English rugby.
There are a number of other new faces for last season's Championship winners, including former Australia Test flanker George Smith and ex-Gloucester prop John Afoa.
"We can't wait to get going," said Bristol head coach Pat Lam. "It should be a great night for the supporters, and the sense of responsibility -- to do our best and play as a team -- goes right across the team because we want to inspire these fans and hopefully they will keep coming back."
"They (Bath) are a new squad with new coaches. They've brought Girvan Dempsey in (as attack coach) from Leinster, who I know from my time at Connacht, and that is a good addition.
"You are aware of what they do and the threat that they pose but the whole focus is making sure that you get your own things right, whether it's on attack or defence."
Wales international centre Jamie Roberts is among three Bath debutants for the trip.
Roberts is joined by midfield partner Jackson Willison and wing Joe Cokanasiga. England flanker Sam Underhill features in a back-row that also includes Taulupe Faletau, while Underhill's Test colleague Semesa Rokoduguni returns from injury on the wing.
Bath rugby director Todd Blackadder said: "I am feeling excitement for the players. I just want us to get out there, unleash and really express ourselves."