And there's probably no-one better placed to guide an English side through the choppy waters, particularly against a side he candidly admits "have made the Heineken cup what it is".
Speaking on Quins website O'Shea, 'can't wait' for today's encounter against a side he openly admires in a competition he obviously wholeheartedly embraces.
"It's what you get into rugby for. Days like this. The quarter final of the Heineken Cup. Only eight teams left and playing against probably the team, in my opinion the team who have made the Heineken cup what it is.
"Their journey, to their ultimate holy Grail, the consistent success they've had but also the heartache along the way. Its kinda proof to every team what you have to go through to ultimately achieve. "It's going to be an incredibly exciting day and we just hope we can deliver the performance our supporters want."
But O'Shea is a pragmatist and not one to be daunted by stats or records. "You're not playing the team that has reached 13 quarter finals you're playing the team you're playing this week." he says.
"But then you look at the players they've got." and he rattles off a host of names before continuing in a deeply respectful drawl. " They're a reaaaally good rugby side.
"People might get carried away by results," he says, possibly referencing Munster's recent less than impressive run, " but we know the performances they can reach.
"I know the passion that they can play with. I know what the Heineken Cup means to Munster people "It's a huge challenge (for us). "Is this going to be the best day the Stoop has ever witnessed ? I think it will. "It will be the greatest atmosphere the Stoop has ever witnessed.
" The Munster support will be incredible. Its going to be loud. "It's going to be a very special day."
Munster: F Jones; D Hurley, C Laulala, J Downey, S Zebo; R O’Gara, C Murray; D Kilcoyne , M Sherry BJ Botha; D Ryan, P O’Connell capt; P O’Mahony, T O’Donnell , J Coughlan. Replacements: D Varley W du Preez, S Archer, Donncha O’Callaghan, P Butler, C Sheridan, I Keatley, I Dineen.
Harlequins: Mike Brown; Tom Williams, George Lowe, Tom Casson, Ugo Monye; Nick Evans, Danny Care; Joe Marler, Rob Buchanan, James Johnston, Ollie Kohn, George Robson, Maurie Fa'asavalu, Chris Robshaw (c), Nick Easter. Replacements: Joe Gray, Mark Lambert, Will Collier, Charlie Matthews, Tom Guest, Karl Dickson, Ben Botica, Matt Hopper.