Quinlan and Sheahan both arrived back on Irish soil yesterday after Ireland's premature exit from the World Cup in France. The pair's experience could be crucial as Munster look to preserve their 100% start to the league campaign and reel in the table-topping Blues, who have two games in hand on fourth-placed Munster.
Coach Declan Kidney has also included giant prop Tony Buckley in his extended squad - Buckley flew out to France late last week to provide Ireland with cover in the front row following Simon Best's hospitalisation.
Munster are expected to reduce their squad to a matchday 22 after training tomorrow and the starting line-up will be announced at midday on Thursday.
Friday's crunch game at Musgrave Park has a 7.30pm kick-off.
MUNSTER Squad: Forwards - Darragh Hurley, Tim Ryan, Tony Buckley, Denis Fogarty, Sean Cronin, Frankie Sheahan, Federico Pucciariello, Mark Melbourne, Mick O'Driscoll, Billy Holland, Niall Ronan, Tommy O'Donnell, James Coughlan, Alan Quinlan, Anthony Foley (capt).
Backs - Shaun Payne, Ian Dowling, Kieran Lewis, Lifeimi Mafi, Rua Tipoki, Anthony Horgan, Paul Warwick, Jeremy Manning, Tomas O'Leary, Gerry Hurley.