WALES international centre Jamie Roberts is among three Bath debutants for the Gallagher Premiership opener at Bristol tomorrow night.

Roberts is joined by midfield partner Jackson Willison and wing Joe Cokanasiga in the line-up for the Ashton Gate clash. 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.

Matt Garvey will captain Bath and starts at second row alongside Dave Attwood.

Jack Walker lines up at hooker, with Nathan Catt and Henry Thomas completing a powerful front row.

Zach Mercer starts at openside with Underhill at blindside and Taulupe Faletau completing the back row at number eight.

Chris Cook will link-up with Rhys Priestland in the half-back combination, with Tom Homer at full-back.

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.

"It's pretty much going to be a full house at Bristol, which is fantastic.

"Hopefully, there will be a lot of Bath supporters there and there wouldn't be a better way of kicking the competition off.

"It's all about pressure, getting the set-piece right and making sure our platforms are good so we can launch from them, get on the front foot and play some really good rugby."

Star signing Charles Piutau will miss Bristol's record-breaking opener.

The west country club's major box office recruit - a reputed £1million arrival from Ulster - is due to see a specialist this weekend.

Piutau suffered a shoulder injury during Bristol's pre-season friendly appointment with Connacht last week, and the full extent of the damage is yet to be revealed.

The New Zealander's absence is a major blow for Bristol on their return to top-flight English rugby, and to the vast majority of a club record 24,000-plus home crowd that will pack Ashton Gate.

He would undoubtedly have featured in a Bristol side that shows several debutants, including former Australia Test flanker George Smith and ex-Gloucester prop John Afoa, as last season's Championship winners face their fierce west country rivals.

"We can't wait to get going," Bristol head coach Pat Lam said.

"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.

"Every week, five points are up for offer, and it's the team that goes out and does it. Predictions are fun, it's good to watch, but nobody can predict sport otherwise many thousands wouldn't come to watch.

"We want to start the season well, and your home games are crucial.

"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."

Bath: 15 Tom Homer, 14 Semesa Rokoduguni, 13 Jackson Willison, 12 Jamie Roberts, 11 Joe Cokanasiga, 10 Rhys Priestland, 9 Chris Cook,

1. Nathan Catt, 2. Jack Walker, 3. Henry Thomas, 4. Dave Attwood, 5. Matt Garvey, 6. Zach Mercer, 7. Sam Underhill, 8. Taulupe Faletau

Replacements: 16. Tom Dunn, 17. Will Vaughan, 18. Anthony Perenise, 19. Elliott Stooke, 20. Francois Louw, 21. Max Green, 22. Freddie Burns, 23. Aled Brew (43).