The No.8 enjoyed a standout campaign for Montpellier Hérault Rugby in 2020-21 and was particularly impressive in the Heineken Champions Cup knockout stage.

Having featured in both pool stage games against Exeter Chiefs, Englishman Mercer produced a stunning display in the Round of 16 first leg against Harlequins, running in two tries and picking up Heineken Star of the Match as Montpellier triumphed 40-26 at the GGL Stadium.

After helping the TOP 14 side hold on for an aggregate victory in the return leg, Mercer was on the scoresheet again in the quarter-finals, crossing in the second half against Stade Rochelais, although he was unable to prevent a 31-19 defeat to the eventual champions.

His three efforts in last season’s competition takes his tally in EPCR competitions to 10 tries in 24 games.

The 25-year-old will be one to keep an eye on as Montpellier take on London Irish and Ospreys in Pool B this season. Gloucester, meanwhile, will look to consolidate their Heineken Champions Cup status after returning to the competition this season.

Gloucester head coach George Skivington told the club’s website: “We’re building a solid group at the club, with very little movement in or out, so to have secured Zach for next season is a testament to the player he is both on and off the field.

“His performances for Bath and Montpellier are evidence enough of his capabilities. He has a top-class work rate, outstanding ball carrying skills and is solid in defence. He will undoubtably bring a further dimension to add to our current backrow.”

Mercer added: “To be given the opportunity to come back and play in the [Gallagher] Premiership with Gloucester is one that I couldn’t turn down. The loyal fans and atmosphere at Kingsholm is something I can't wait to be part of.

“I have another season here with Montpellier and I’ll be giving all my focus to the club in trying to secure back-to-back titles and European cup success.”

Zach Mercer will join Gloucester Rugby ahead of the 2023-24 season, the Heineken Champions Cup Pool A side have confirmed.