Argentina star Felipe Contepomi will make his first start for Leinster in Saturday's Celtic League clash with Neath/Swansea Ospreys.
Coach Gary Ella welcomes back his World Cup players and has selected a formidable line-up for the game at The Gnoll.
Much will be expected of Contepomi who lines out at out-half while Brian O'Driscoll, Shane Byrne, Malcom O'Kelly, Eric Miller, Keith Gleeson and Victor Costello all return to the blue jersey.
Prop Reggie Corrigan also returns from duty Down Under and will captain the side.
Shane Horgan, however, has an arm injury and will miss the game but he is expected to be fit for the Heineken Cup opener against Biarritz early next month.
Ulster coach Alan Solomons is boosted by the return of Ireland out-half David Humphreys for the province's game against The Borders at Ravenhill on Friday.
LEINSTER: G Dempsey; J McWeeney, B O'Driscoll, D Quinlan, G D'Arcy; F Contepomi, B O'Meara; R Corrigan (C), S Byrne, P Coyle; M O'Kelly, B Gissing; E Miller, K Gleeson, V Costello.
ULSTER: B Cunningham; J Topping, R Constable, P Steinmetz, T Howe; D Humphreys, N Doak; S Best, M Sexton, R Moore; M Mustchin, R Frost; A Ward (c), N Best, R Wilson.