John Cooney links up with Noel Reid at half-back after players saw action as replacements in Leinster's RaboDirect PRO12 derby win over Munster.
Collie O'Shea, who has featured for Clontarf in the Ulster Bank League lately, will partner Brendan Macken in the centre.
In the pack, McGrath starts in the front row alongside hooker Thomas Sexton and Jack O'Connell, with ex-Leeds second row Tom Denton packing down with Ben Marshall.
* There will be free entry for Leinster Season Ticket holders for all British & Irish Cup pool games upon presentation of this year's membership card.
LEINSTER 'A' (v Leeds Carnegie): Darren Hudson; Andrew Boyle, Brendan Macken, Collie O'Shea, Sam Coghlan Murray; Noel Reid, John Cooney; Jack O'Connell, Thomas Sexton, Jack McGrath (capt), Tom Denton, Ben Marshall, Jordan Coghlan, Josh van der Flier, Jack Conan.
Replacements: James Tracy, Tadhg Furlong, Tadhg Beirne, Dan Leavy, David Shanahan, Cathal Marsh, Tom Daly.