The British and Irish Lion, who has scored two tries in three EPCR Challenge Cup matches this season, started both of Scotland’s Six Nations games and comes straight back into the Worcester XV.

The hosts, who have completed their EPCR Challenge Cup Pool A fixtures and need favourable results elsewhere in Round 5 in April to secure a place in the Round of 16, have made four changes to the side beaten at Sale Sharks last weekend.

Along with van der Merwe, Worcester have brought in a fresh back-row amid a spate of injuries, with flankers Joe Batley and Matt Kvesic lining up with No.8 Sione Vailanu.

In the United Rugby Championship, Edinburgh Rugby are also boosted by returning Scotland talent, with flanker Nick Haining, scrum-half Ben Vellacott, fly-half Blair Kinghorn and centre Mark Bennett all starting as they travel to Munster Rugby.

Elsewhere in the United Rugby Championship on Friday, scrum-half Jamie Hill will make his first appearance of the season as Cardiff Rugby entertain Zebre Parma.

Cardiff, who will enter the EPCR Challenge Cup Round of 16 following their elimination from the Heineken Champions Cup, have also called in prop Brad Thyer.

No.8 Taina Fox-Matamua and scrum-half Manfredi Albanese could make their debuts from the bench for Zebre, a side who have slipped to three defeats in three EPCR Challenge Cup Pool A games this season.

Winger Duhan van der Merwe returns from Scotland duty as Worcester Warriors welcome Bristol Bears in the Gallagher Premiership on Friday night.