The 24-year-old, who will be the fourth and final overseas player on Ulster’s roster, has been capped 28 times and scored six tries for his country. The versatile forward, who can operate across the back row, led the Sharks on their pre-season game against Toulouse last night.
His additions is a major boost to the Les Kiss’s side, who also have All Black wizard Charles Piutau coming next season after his loan spell to Wasps. Callum Black will lead out the Pro12 leaders this evening at the Kingspan Stadium against Glasgow in celebration of his 100th appearance for the province.
Black is one of a number of changes to the side that defeated Dragons last week. With Ian Humphreys sidelined with concussion Paddy Jackson, just returned from Ireland squad training, is on a very strong bench. Sam Windsor makes his first start in the number 10 jersey while Stuart Olding is moved to full-back and Stuart McCloskey starts in midfield.
Up front, Franco van der Merwe is back in the engine room with Williams back in the number 8 jersey.
Glasgow, meanwhile, have five Scottish squad members available with Gregor Hunter making his first start at fly-half. Ryan Grant, Pat MacArthur and Sila Puafisi will pack down up front, while Peter Murchie starts at full-back with Rory Hughes and Lee Jones on the wings.
S Olding, C Gilroy, D Cave, S McCloskey, J Stockdale, S Windsor, R Pienaar; C Black, R Herring (capt), R Lutton, A O’Connor, F van der Merwe, R Diack, S Reidy, N Williams.
J Andrew, K McCall, B Ross, C Henry, R Wilson, P Marshall, P Jackson, S Arnold.