Centre Ben Te’o returns for Worcester to make his first appearance of the season in the European Challenge Cup against Ospreys.
Te’o missed the first seven games of the season because of a quadriceps injury and has been named in the England squad for their training camp in Portugal next week.
Ted Hill, aged 19, has also received his first England call-up and will start at flanker for Worcester on Saturday.
Tiaan Thomas-Wheeler is set to make his first start for the Ospreys as Rhodri Jones makes his 50th club appearance.
Ospreys Head Coach, Allen Clarke, said: “Our challenge is to focus on what we do well and ultimately deliver an individual and team performance to be proud of.”
Chris Ashton will make his debut for Sale after a seven-week suspension for their tie against Connacht.
Ashton will play on the wing and is one of five changes to the starting 15. Bryn Evans, Ben Curry and James O’Connor return to the side as Josh Beaumont moves from lock to number eight.
England international Jack Clifford returns for Harlequins to face Grenoble in France.
Clifford has not played since the end of last season and will return alongside Francis Saili who has been out since April.
Head of rugby at Harlequins, Paul Gustard said: “We want to continue moving our whole game forward as we aim to be more destructive in our defence, more threatening in our attack and more consistent in our set piece.”
After their 43-22 home win over Zebre last week, Bristol will make six changes for the return game against the same opponents.
Piers O’Conor and Jordan Crane recover from injury to start as Harry Randall and Steven Luatua are also included.
Jake Heenan will make his first start, and Sam Bedlow his first competitive start for Bristol against the Italian side.
Bristol head coach, Pat Lam, said: “Zebre will be a different beast in front of their home supporters and we need to embrace the challenge that awaits us in Parma.
“It’s a fantastic place to play rugby and we’re looking forward to the occasion.”
In the other games in the Challenge Cup on Saturday, Clermont Auvergne host Timisoara Saracens, Stade Francais visit Pau and Bordeaux Begles host Perpignan.