Ulster head coach Richie Murphy has named his team for the BKT United Rugby Championship Round 6 match against Cardiff on Saturday - with no sign of hooker Rob Herring in the squad.
Ulster line-up doesn't bode well for Ireland's burgeoning injury crisis.
The Hurricanes are still months away from starting preseason training but are already facing a playmaker crisis thanks to an ACL injury befalling starting No. 10 Brett Cameron.
Ulster fell to a 35-22 loss to Lions in Johannesburg but could take some encouragement from a point on the road in the United Rugby Championship.
A dramatic late try with the clock well in the red from David Shanahan ensured that Ulster opened their United Rugby Championship season with a 20-19 win over champions Glasgow Warriors.
Duffy previously assisted Murphy as part of the Ireland U20s management and he has now taken up the offer to switch from Perth to Belfast to rekindle their working relationship.
Ulster have confirmed the signing of Irish-qualified fly-half Aidan Morgan from the Hurricanes on a two-year deal.
Captain Brad Shields has called on the Hurricanes to “tighten the screws” ahead of a blockbuster clash with the Chiefs at FMG Stadium next week.
The Hurricanes remain on track for a top-two finish in Super Rugby Pacific this season after overcoming a valiant Moana Pasifika side.
