GUINNESS PRO12: Ruan Pienaar starts at outhalf for Ulster against Leinster

Trimble is back from a foot injury while Paul Marshall, Darren Cave and Tommy Bowe are also handed starts.

Leinster make 12 changes but fly-half Jonny Sexton has failed to recover in time from a hamstring injury.

Ulster have rested Ireland trio Rory Best, Paddy Jackson and Iain Henderson for the trip to Dublin.

Marshall’s inclusion at scrum-half means Ruan Pienaar shift to fly-half, while Cave will partner Stuart McCloskey in midfield.

Bowe and Trimble will be joined by Charles Piutau in the back three.

Forwards Rob Herring, Franco van der Merwe and Sean Reidy have also been promoted to the starting team as Ulster director of rugby Lee Kiss makes seven changes.

Ross Byrne, captain Isa Nacewa and Rory O’Loughlin are the only players to keep their places in the Leinster side following the Boxing Day defeat by Munster.

Leinster fielded an under-strength side at Thomond Park but many of their big names are back including a formidable back-row of Sean O’Brien, Josh van der Flier and Jamie Heaslip.

The hosts are unbeaten in their last 18 Pro12 matches at the RDS.

Leinster: A Nacewa (capt); A Byrne, G Ringrose, N Reid, R O’Loughlin; R Byrne, L McGrath; J McGrath, S Cronin, M Bent, D Toner, H Triggs, S O’Brien, J van der Flier, J Heaslip.

Replacements: R Strauss, A Porter, J Loughman, M Kearney, J Conan, J Gibson-Park, T Daly, Z Kirchner.

Ulster: C Piutau: A Trimble, D Cave, S McCloskey, T Bowe; R Pienaar, P Marshall; A Warwick, R Herring (capt), R Ah You, K Treadwell, F van der Merwe, C Ross, S Reidy, R Wilson.

Replacements: J Andrew, C Black, J Simpson, P Browne, C Henry, B Herron, L Ludik, J Stockdale.