South Africa World Cup winner Duane Vermeulen will make his Ulster debut in Saturday's Heineken Champions Cup opener away to Clermont Auvergne.

Vermeulen, who only met his new team-mates in person for the first time before flying to France on Friday, starts at number eight.

Marcus Rea also starts for Ulster.

Rea and Vermeulen, who will link up in the back row alongside Nick Timoney, are two of five changes made by Ulster head coach Dan McFarland from the team that lost last week away to Ospreys in the United Rugby Championship.

Andrew Warwick comes in at loose-head and Rob Herring at hooker to join tight-head prop Tom O'Toole in the front row, with Alan O'Connor captaining the side in the second row alongside Kieran Treadwell.

The only change to the backline sees Ireland international James Hume starting at centre in place of Angus Curtis, who drops out of the matchday squad.

Front row trio Bradley Roberts (ankle), Marty Moore (concussion) and Tom Stewart (foot) sustained injuries during the loss to Ospreys and are unavailable for Ulster's Champions Cup opener.

Nathan Doak and Stewart Moore provide the back options on a bench that includes six forwards, with back-row Sean Reidy in line to make his 150th appearance.

Speaking this week, McFarland remained coy about his new signing's chances of starting, saying that it was "complicated" and that the club were monitoring him.

Ulster had announced that Vermeulen was isolating last Tuesday having arrived in Belfast before testing positive, following South Africa's autumn Tests and the Barbarians game with Samoa which was called off at the 11th hour following a positive case in the squad.

Ulster: Lowry, Baloucoune, Hume, McCloskey, McIlroy, Burns, Cooney; Warwick, Herring, O'Toole, O'Connor (Capt), Treadwell, Rea, Timoney, Vermeulen.

Replacements: Andrew, McGrath, Kane, Carter, Jones, Reidy, Doak, Moore.