Ireland's greatest hooker is a long way off an Ireland no8

Leinster's running Dan Sheehan at no8 against Munster worked very well - they won.

His 17 carries were the most for any player although Leinster did have 62 percent possession while three of the other five starting back-rows played less than an hour.

Gushingly exciting, maybe, but it was not a new frontier.

It wasn't Andy Farrell's idea - and if it was he should be ashamed - and had nothing of Rassie Erasmus's mash-ups, how-to-exploit-the-bench and Bomb Squad nuances.

Leinster pulled off a tactical coup by backing themselves to be the attacking team at a time when thanks to Caelan Doris, Jack Conan and Josh Ericson being injured their numbers were low.

It can't be stated definitively that the likable Dubliner won't start at no8 for Leinster again but it's highly unlikely for, at least, three reasons.

Take those 5m scrums, normally an area where the no8 is in charge, it's his decision as to what's going to happen. Leinster's pragmatism had given Jamison Gibson-Park this responsibility. JGP makes the play ahead of Ryan Baird's try.

On the other side of the set scrum, Gavin Coombes and various other back-row launches gained more metres than normal in a sport that prizes every inch of front-foot possession.

Sheehan, at the back of the lineout, was neither a credible jumping nor defensive option (although he did win a lineout - and laid it off perfectly - but it was at the front).

Three areas that are open to prying DVD eyes. Those who have the action replay button would summon eight-man lineouts; dial-up the number of attacking back-row moves; police the other players who are 5m scrum options more vigilantly.

Leo Cullen, Farrell, all of us, can beam with pride that this hooker is such a gifted player, be happy to note there is an option to switch him mid-game should the need arise.

And Jeez, Ireland could start Sheehan at no8 against some of those numpty World-Ranked 15-plus teams where Ireland have 75/85 percent possession.

But using him against a USA, Chile, Spain, Uruguay, Tonga, Samoa, Romania, Canada (literally WR 15-22 at the minute) would be denying a fringe player productive game time.

Don't just take my word for it: I was able to give Leinster's Forwards Coach Robyn McBryde - possibly the biggest rugby 'purist' working in Irish rugby - a hard time about the wash.

Given a lob McBryde was willing, good-naturedly, to bat for his player: "There was nothing there to show that Dan couldn't do it again, at the end of the day, you want your best rugby players on the field. That performance was a no8 as a ball player.

"He gets across the gain line, he runs out and into the contact, he's got lovely skills. You want the ball in your eight's hands as much as possible.

"Other than starting to cramp up, whether that was because of a few more running metres or whatever, Dan had plenty of carries to his name.

"It was probably taking advantage of the fact that, because we took the squad out to South Africa, players had to double up in certain areas.

"Dan brings a lot of attributes naturally to that position anyway. Did you see him jumping in the line-out as well? He won a ball at the front."

Okay, change of bowling, Foley from the non-Pavilion end.

Can you be sure Dan has the defensive/attacking triangulation needed across the back-row (no6, no7, no8 together) - vital for the steps up to Champions Cup and onto Test rugby - right?

Or that the back of a Champions League Leinster and Ireland lineout could operate with a player not recognised as a solo jumper or practiced at being lifted?

"Listen, you can make cases for and against depending on the opposition you play against. For his first game there, there's nothing that's saying he couldn't play there again.

"If he wanted to develop that, you'd have to play him there a bit more, get him more familiar with the small subtleties and the nuances of what it's like to be in that position a little bit more.

"You'll only gain that experience by spending time there and if that's going to take too much away from his game as a hooker, that's the balance, because he's an out-and-out, world-class hooker as well.

"Because of injuries, our hand was forced a little bit, but I just think he came through it very, very well.

"The modern game is about having your best players on the field, players who can probably cover a little bit more than one position."

Put simply there was a lot of things at play going into last weekend where it was hardly about new frontiers just about the one-off.

"You had Jamison's first game back from injury, you had Joey Carbery's first game, so you're talking about the eight-nine-ten combination there.

"Was it as smooth as it could be? No, it wasn't, because it was the first time everybody played together."

The lineout can be a very precise thing where the timing of the throw, the lifters and jumpers needs precision, it would be difficult to just pick it up at training the week before a game.

"I don't doubt it, but he can do a job for you depending on the make-up of your back-five. If you've got three, even four jumpers making up that back five, then there's room for one who can't."

"We knew that, but was it a risk worth taking? Yes, of course, it was a risk worth taking. If you wanted to improve in that position, you'd have to play there a bit more often.

"You look at versatility, they use it in France better than anywhere, really, where you can get them playing in any position in the back-five from one week to the next.

"They have that ability to do it. Cameron Woki (Racing, Bordeaux & France) jumps to mind - from second-row to back-row, whatever, he is just a tremendous football player so you do get those players.

McBryde also hints there was a bit of devilment involved last week with selecting Sheehan - maybe part encourager les autres.

"We have good, honest meetings with players, just to make sure that they're completely aligned with how we see them and how they're progressing, and what they need to work on to get better.

"On the back of the conversations we've had, that was the reason we said, listen, these are Dan's strengths that we see, it's what we feel we need from an eight.

"He's a good ball carrier. He'll get you across the game line. He's a good distributor.

"We just felt we needed that for this game against Munster, who, as they showed in the first-half, were very effective in the breakdown in and around the contact area."

Sheehan at no8 was Leinster more knowing they would dominate possession, less Farrell, Erasmus, reinventing the wheel and possibly more lighting a fire under others perceived as content to be professional reserves.