SAM Underhill will make his Bath debut tomorrow night against Northampton Saints in the Aviva Premiership at Franklin’s Gardens (7.45pm).

Underhill is one of four changes to the starting line-up that beat Saracens 31-21 last time out, with Ben Tapuai, Kahn Fotuali’i and Charlie Ewels all making their first starts of the season.

England international Underhill lines-up in the back-row with Taulupe Faletau and captain Matt Garvey. Ewels comes in to the second row alongside Elliott Stooke, whilst the front-row is unchanged.

Fotuali’i, who came on early in the first-half last week at the Rec, links up with Rhys Priestland in the half-backs, as Tapuai joins Jonathan Joseph in the midfield.

Semesa Rokoduguni, who has scored three tries in two games, and Matt Banahan start out wide, with Anthony Watson at full-back.

Bath rugby director Todd Blackadder said: "I think it's an exciting challenge.

"They (Northampton) are a good team, and our challenge is to keep replicating the same performance.

"We need to go there and start really physical, and if we do that then the mindset will be right. We have got to turn up mentally."

England and Northampton captain Dylan Hartley will miss the clash.

But Northampton say that Hartley, who has a hand injury, and flanker Tom Wood (shoulder) are "anticipated to be in training next week."

Hartley, who scored a try when Saints saw off Leicester last weekend, is replaced by Mikey Haywood, with Courtney Lawes leading the side.