CIAN HEALY’S INJURIES may have caught up with him yet again, but it’s now come to pass that even if he were flying fit, he’d probably have been facing Wales this weekend with number 17 on his back.

Jack McGrath’s rise in the last 24 months hasn’t been meteoric, but it’s most certainly been consistent.

Instead of peaks and troughs, he’s provided a steady and increasing return on investment, soaking up the minutes like a sponge, to the point where a Cian Healy injury no longer strikes fear into the Irish or Leinster fan like it once did.

It’s no disrespect to McGrath to say that in the majority of his 13 test starts to date, Healy’s absence has been the cause.

However, despite his provincial teammate rehabbing an injury at the moment, the feeling is that had he been available at Carton House this week, he’d have been providing impact from the bench.

McGrath’s challenge this week is to lead. Not only has he muscled his way into the number one jersey, but he’ll be in a Six Nations starting line-up that doesn’t contain Mike Ross, with both Nathan White and Tadhg Furlong still new to the test game.

Opposite McGrath will be Samson Lee, who has struggled at scrum time since returning from his horrific achilles tear 11 months ago.

The pair were in direct competition when Ireland played Wales in last season’s Championship, but the Welshman’s injury ended that contest on the opening scrum of the day.

While he had looked to be a strong and powerful scrummager prior to that injury, something hasn’t looked right since.

Against Connacht in the Pro12 at the start of January he found himself packing down opposite Finlay Bealham, who had little trouble holding his own.

The majority of scrums stayed up, and both teams sent the ball in and out without problems, but one first half penalty that Bealham won from Lee shows the type of footwork that McGrath can expose on Sunday.

If McGrath can lower the height of the scrum and keep his back straight, he could cause a problem for Lee.

As we can see below, the Scarlets prop does have a tendency to keep his feet a little too far back from his body, which leaves him prone to dropping onto his knee.

In the picture below, watch the yellow line tracing Lee’s body position. While his back is nice and parallel to the ground, his feet are too far back, with the red line giving an indication of where his legs should be positioned.

By having his feet even those extra few inches too far back, it means that his balance is compromised. And inevitably, he collapses, with a Connacht penalty an easy decision.

In Lee’s most recent outing he found himself up against the Northampton Saints, whose scrum has been arguably one of the best in Europe this season.

Again he struggled, with Alex Waller giving him trouble from the first scrum of the game.

While in the previous scrum he was caught out by having his feet too far back, it was the position of his back that caused the biggest problems on the opening drive of this game.

In the initial image, all seems fine. His feet aren’t too far behind his body, while his head is level with his hips.

However, before the ball is even fed, he is struggling with the pressure from Waller.

He steps back and starts locking his legs, while his head and shoulders begin to rise.

With his body position so poor, as soon as Waller begins to exert any real pressure, Lee starts to stand up.

He also shifts his bind, lifting it over the Saints prop as he turns in, and it’s an easy penalty for the referee to award.

Later in the half, the Scarlets were awarded a penalty, but it was very, very fortunate, with Lee once again exposed.

If we examine how the pack sets up, Lee’s bind is worth taking note of.

He has far too loose a hold of Ken Owens’ jersey, which means that he and his hooker can be easily separated.

When the bind is wrong in the front rows, it means that everything begins to fall apart much easier.

Just like the previous scrum, his head and shoulders lift above his waist (they should form a line parallel to the turf), and he’s already dropped to his knee, with the ball not even in the scrum.

Eventually the ball is fed, and Lee gets lucky. With his own positioning such a mess, he gets turned inside easily by Waller, but it’s the Scarlets who get the penalty, after Saints scrumhalf Tom Kessell foolishly pushes over Gareth Davies.

It’s also deemed that the Saints wheel the scrum illegally, although that looks questionable, with Waller only turning in after Lee has already popped up.

Lee’s footwork looks to be his biggest problem though.

In many instances, he’s dropping to his knees when he comes under pressure, and it could partly be down to the horrific injury he picked up against Ireland last year.

It happened in the opening scrum of the day, when he drove too hard from too low a position, before his achilles tore on the spot.

If you closely look at the left of the gif, you can see how Lee plants his foot too far back, to the point where his shin is almost parallel to the ground.

While the injury itself is healed, the impact of it could still be present in Lee’s game. Scrummaging can often be a mental skill, and the memories of that scrum could be impacting on his ability to trust his leg power.

Towards the end of the first half, he collapses before the ball is even fed once again. It’s reset by the referee, but the rest follows a similar path.

Once again, we can see the angle at his stomach being far too obtuse (it should be 90 degrees, but his is closer to 120), while his head is once again above his hips, with his body pointing upwards.

When he drops to his knees, he’s penalised, but we can also see how his bind could have impacted the collapse. He appears to be bound to the arm of Waller, dragging him down to the ground.

This is set to be McGrath’s fourth game against Wales in under 12 months, and while he only got to face Samson Lee for one scrum in that time, he fared well against the Welsh replacement for this coming game – Tomas Francis – during the World Cup warm-up meeting at the Aviva Stadium in August.

Francis struggled to budge the Irish loosehead that day, with this early scrum showing how McGrath simply holds his position, allowing simple ball retention for Conor Murray, creating a platform for the backs to attack.

However, he was also prepared to take advantage and exert his dominance when the opportunity arose.

This scrum close to the Welsh line presented an ideal opportunity, and he exploited Francis’ poor body position .

We can see below how Francis has far too much of an arc in his back, with McGrath keeping his straight and low.

And the arc only becomes more pronounced once McGrath starts to push.

And when we watch it back in full, we can see how Francis resorts to walking backwards, unable to stop McGrath’s drive. He got his body position wrong, and from there, he was powerless to stop the drive.

In the absence of Healy and Ross in the past few weeks for Leinster, McGrath has been influential in the front row.

In their 22-9 win against the Ospreys last month, he put in two huge drives in the opening 10 minutes on Aaron Jarvis, who failed to make the cut for the Welsh this weekend.

In the first scrum, they were unlucky not to be rewarded with either possession or a penalty, with McGrath gaining several yards on the far side of the picture, and Tadhg Furlong holding his own against Paul James.

Shortly after though they were rewarded when McGrath once again walked through Jarvis. He’s on the far side of the picture so we can’t see the mechanics of it, but it’s a huge shove so close to their own line.

However, if there is an area that McGrath needs to work on, it’s his propensity to wheel.

Occasionally he steps to the left and pushes off his outside toot to try wheel the scrum around, and it’s something he was pinged for later in this game.

Rather than stepping forward, he can be seen to rotate on the spot, and it’s something he was caught out for in this instance.

It isn’t something he always does, but he can often be caught for doing it in games when he’s comfortably dealing with his opponent.

It happened in the early stages of the warm-up game against Wales. As we saw earlier, he had very little difficulty dealing with Tomas Francis, but still got pinged for stepping sideways and wheeling.

And despite being well in control against Aaron Jarvis when the sides met in the 2015 Six Nations, McGrath also found himself pinged for an identical infringement.

Keep a close eye on his left leg, and watch how it moves out to the side, rather than pumping forward.

If he avoids this, McGrath has the form and the strength to give Samson Lee real problems.

On the other side of the scrum, Nathan White and Tadhg Furlong will feature at tighthead, with White probably just about ahead of the Leinster man for a starting jersey.

Up against him will be Rob Evans, who surprised many by getting the number one jersey over the experience of Gethin Jenkins.

It looks to be a smart call, however, with Jenkins’ form over the last two years falling well below what we had been used to over his career.

Evans and White met only a few weeks ago in the Guinness Pro12 at Parc y Scarlets, and it was one of the cleanest scrum battles I’ve ever seen.

Both players kept square and straight, with good positioning and footwork, and the vast majority of scrums saw the ball go in and out in a matter of seconds.

I’m not expecting as straight-forward a battle this Sunday, but if White can keep Evans stable, McGrath can exploit Lee and give Ireland the platform for victory.

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