Leinster 'A' enjoyed a fine 47-18 victory over Leeds Carnegie in their cup opener, and this week Noel Reid moves to full-back in place of Darren Hudson who injured his shoulder in the last minutes of the Leeds game.
John Cooney will partner Cathal Marsh at half-back, with Collie O'Shea continuing his centre partnership with Brendan Macken.
Up front, Ruddock joins Jordan Coghlan and Leo Auva'a in a strong back row trio, while Martin Moore starts at tighthead prop in a front row which features Tom Sexton and skipper Jack McGrath.
LEINSTER 'A' (v Pontypridd): Noel Reid; Andrew Boyle, Brendan Macken, Collie O'Shea, Sam Coghlan Murray; Cathal Marsh, John Cooney; Jack McGrath (capt), Tom Sexton, Martin Moore, Tom Denton, Ben Marshall, Rhys Ruddock, Jordan Coghlan, Leo Auva'a.
Replacements: James Tracy, Jack O'Connell, Tadhg Beirne, Jack Conan, David Shanahan, Steve Crosbie, Tom Daly.