"I'd say Jacques Nienaber had a say in it, Andy Farrell may also have made a call on it. We don't have the luxury in the depth chart that France and South Africa have in the back row."

Leinster have decided to take a massive leap of faith and move Dan Sheehan to no8 for the game with Munster this Saturday. The Blues are switching their star hooker, known for his all-court game, and putting him into a position where they hope he can cause maximum damage with ball in hand. Alan Quinlan says it reflects Rassie Erasmus's thinking: move players with suitable skills around the pitch. At the same time, Ian Madigan notes that Leinster's executive playmaker is the scrum-half so they aren't as reliant on decision-making from their no8. Moreover both Quinlan and Madigan darkly wonder whether the decision, predicated by the injuries to Jack Conan and Caelan Doris, was a request from above, especially since Conan and Doris are also unavailable for Ireland? Has Andy Farrell asked, 'Can I please have a look-see at Dan in the back-row?' "That's a mad one," says Quinlan of Leinster opting for Sheehan at no8. "I just think he's such a good player. We probably saw him playing in the back row-before. "He did it top level, AIL anyway, and it's just that he's such an outstanding athlete. "Rassie Erasmus has probably started this scenario with certain players: back-rowers playing at hookers, centres playing in the back row, back-rowers playing out in the back line. "So I think it's just Leinster have those injuries there with Doris and Conan in particular and they just want to have Dan Sheehan on the field because of his ability to carry and do damage in the loose. "It's a little bit of a left-field selection but the athlete you have in him, he's well capable of doing that and playing there." The no8 is considered the pre-eminent player among the forwards not necessarily the best on the ball, the most dynamic runner, the best defender or the best at the lineout. But in overall terms he is supposed to average out as the best when all the skills are taken into account. That's why moving players between positions is considered risky. What do hookers know about jumping and catching in lineouts? What do props know about taking options from the back of the scrum, etc. Says Madigan: "It depends on your core position and what position you're moving to and then it also depends on your athletic ability so if it's an out-half moving to full-back and he doesn't have top end speed it's going to be very difficult for him. "If he's particularly short in the new world of aerial contests it's again going to be a real challenge for him. If it's a prop moving into the second-row, that's also a challenge. If you look at back-rows moving into the second-row, so often we see that they're not as explosive around the pitch. "That's because the likes of scrums and mauls and the workload that they have to get through around the pitch just takes their legs away but then Sheehan has proved himself an extraordinary players across all parts of the game if his on-field snippets are any judge. "What's unique about Dan Sheehan's skills is he can fit them into the 15 and the 23. "He'd be your starting hooker, you'd probably have him in the back-row somewhere, you might be able to play him at no12 and you'd have a few positions where he could come off the benches in impact so he's just that athletically gifted so I think it's an interesting one for him playing no8. "I think first off I'd say it'll be a bit of a relief heading into a game not having to concern himself with the line-outs and where he's throwing to.

"He'll certainly enjoy picking the ball off the back of the scrum and I'm sure he's spent the week practising controlling the ball as it's being fed back to him and also just the role change of where the back-row picks up on phase play. "Besides in the Leinster system, the hooker actually spends a lot of time on the edge and we saw how effective he was in the Cardiff game being the second man in from the touchline.

"So he's very comfortable finding himself in the shape either playing off no9, off no 10 in the middle or holding the width, and his footballing ability and awareness of space and core handling allow him to do that."

Does Madigan think this will be a success? "Yes, I do, but do I think he'll be a long-term option there? I don't think so. This week is about getting your best players on the pitch, it allows them to have Ronan Kelleher and Sheehan on the pitch at the same time.

"I'd say Jacques Nienaber had a say in it, Andy Farrell may also have made a call on it. We don't have the luxury in the depth chart that France and South Africa have in the back row."

Besides says Quinlan, sure there is nothing new under the sun - Munster are past master are adapting to situations like this! "Around 2002 Denis Leamy played outside-centre for Munster, David Wallace on the wing, because Alan Gaffney wanted to have Alan Quinlan, Anthony Foley, Jim Williams, David Wallace and Denis Leamy on the pitch at the same time! "Wally wasn't too comfortable on the wing, Leamy did quite well but probably didn't have the gas in that outside channel. "But I genuinely wouldn't be surprised if Dan Sheehan wasn't an option in the back-row for Ireland at some point, it could happen this November, especially with two world class No8s gone for Ireland. "Who knows, Rassie has done it very effectively, Deon Fourie going in at hooker in a World Cup final a couple of years ago.

"Marco van Staden is a back-row wow playing in the centre, and centre Andre Esterhuizen is effective when goes into that back-row so this is not something I'd be against." The purists will point to a potential glitch: the no8 is often a team's 'executive' officer, he makes snap decision as set-pieces unfold.

How can Leinster's Joey Carbery at no10 - the other executive decision-making position - know Sheehan's thinking as the play unfolds? Madigan doesn't see this as a problem as Gibson-Park's presence will be key:

"I think that's what they'd have been working on during the week. "For Leinster and Ireland the exec is the no 9, JGP is the one pulling the strings, and he is so supreme in his decision making that a lot falls on his shoulders, similarly to Dupont and Lucu.

"Everyone is going to be helping him, hold your feet, be patient, the play will come to you, "But Dan is so physically gifted it doesn't really matter, it's about getting the ball in his hands and imposing himself on the opposition, he's that good." LEINSTER: Hugo Keenan; Tommy O’Brien, Jamie Osborne, Robbie Henshaw, Jimmy O’Brien; Joey Carbery, Jamison Gibson-Park; Andrew Porter, Rónan Kelleher, Tadhg Furlong; Joe McCarthy, James Ryan; Ryan Baird, Josh van der Flier, Dan Sheehan - captain. Replacements: Gus McCarthy, Alex Usanov, Thomas Clarkson, Conor O’Tighearnaigh, Scott Penny, Fintan Gunne, Caspar Gabriel, Charlie Tector. MUNSTER: Ben O’Connor; Shay McCarthy, Seán O’Brien, Alex Nankivell, Shane Daly; Charlie O’Shea, Craig Casey; Josh Wycherley, Marnus van der Merwe, Kieran Brookes; Fineen Wycherley, Tadhg Beirne – captain; Jack O’Donoghue, Alex Kendellen, Gavin Coombes. Replacements: Max Clein, Mark Donnelly, Michael Ala’alatoa, Seán Edogbo, Brian Gleeson, Ben O’Donovan, JJ Hanrahan, Gordon Wood.