Iain Henderson will make Heineken Cup debut for Ulster after replacing the injured Nick Williams for Friday’s Pool 4 opener against Castres Olympique.

Williams has failed to recover from a rib injury so 22-year-old Henderson will make his fourth appearance for the province at blindside flanker.

Henderson has just signed his first full contract, which will keep him at the club until June 2015.

Stephen Ferris switches to the back of the scrum as a result of Henderson’s inclusion.

"I can’t wait. I’ve been watching games at Ravenhill since I was a kid..." - Iain Henderson

The only change on the replacements bench will see Ruan Pienaar, who returned from Rugby Championship duty with South Africa earlier in the week, named on the bench in place of Michael Heaney.

After missing most of last season with an Achilles tendon injury, full back Jared Payne will also make his European bow.

Looking ahead to the game, Henderson said: “I can’t wait. I’ve been watching games at Ravenhill since I was a kid and I’m really looking forward to pulling on the white jersey and experiencing the atmosphere as a player.

“My first aim for the season was to be involved in a few PRO12 games but with the few injuries that we have in the back row, I’ve been given an opportunity and I have to try and grab it with both hands.

“Castres are a very physical team but they also throw the ball wide and have an expansive kicking game. That should make for a tough, but entertaining game. We’ll have to work really hard to nullify their threats.”

Ulster XV & replacements to face Castres Olympique at Ravenhill in the Heineken Cup, Friday at 8pm:

(15-9): J Payne; T Bowe, D Cave, P Wallace, A Trimble; P Jackson, P Marshall;
(1-8): T Court, R Best, J Afoa, J Muller (c), D Tuohy, I Henderson, C Henry, S Ferris;

Replacements (16-23): R Herring, C Black, A Macklin, L Stevenson, M McComish, R Pienaar, L Marshall, C Gilroy.