With Stringer out of international favour during the RBS Six Nations his availability to Munster resulted in O'Leary getting very little game time and management feel it prudent to address that situation with the next stage of the Heineken Cup looming.
In the pack coach Declan Kidney retains the same back row that started in Cardiff but in the front row Marcus Horan comes in for Federico Pucciariello and fit again Jerry Flannery gets much needed game time ahead of Frank Sheahan.
Mick O'Driscoll's experience gives him the nod over Donnacha Ryan who is named on a very strong looking bench that includes Sheahan, Stringer and internationals John Hayes and Donncha O'Callaghan.
Kidney Quote:
"We are fully focussed on tomorrow's game. Its a huge ganme for us because we are fully aware that we have to win our remaining seven games to put pressure on the League leaders.
"Ulster have won all their games since the appointment of their new coach Matt Williams, so they've built up momentum and we know we are up against it tomorrow.
"Its great of course to have the internationals back, to be working again with a full squad. But those not involved at international levels have trained well and worked hard in the period when the others were away. The team we've selected for tomorrow reflects that I believe."
Munster Team:
1 - Marcus Horan, 2 - Jerry Flannery, 3 - Tony Buckley, 4 - Mick O'Driscoll, 5 - Paul O'Connell (captain), 6 - Alan Quinlan, 7 - Niall Ronan, 8 - Anthony Foley, 9 - Tomas O'Leary, 10 - Ronan O'Gara, 11 - Ian Dowling, 12 - Lifeimi Mafi, 13 - Kieran Lewis, 14 - Doug Howlett, 15 - Denis Hurley
Replacements: 16 - Frank Sheahan, 17 - John Hayes, 18 - Donncha O'Callaghan, 19 - Donnacha Ryan, 20 - James Coughlan, 21 - Peter Stringer, 22 - Paul Warwick,