This weekend sees the semi-finals of this season’s European Rugby Champions Cup take place, with four teams all vying to make it to the Aviva Stadium and get their hands on the trophy.

However, the route for all four is far from easy, with every one of them very capable of winning this weekend and sealing their place in the last two, and so all four will need to be at the top of their game in order to progress to next month’s showpiece event.

With the lineouts now out for all four sides, here are four players who could make the difference for their sides on the day.

Dan Sheehan (Leinster)

The Ireland hooker is a player that Leinster fans have come to love in recent seasons, with him not the archetypal front rower who carries a lot of weight and bulk, but still just as effective at the top of the scrum whilst also showing his ability to make the types of breaks that would be expected of a back rower or even a back.

For Leinster, he has become a central part of their ability to play on the front foot through making dominant collisions and exploiting gaps in opposing defensive lines, and they will be relying on him to show his quality at the breakdown against Toulouse, as well as his set piece threat, in order to prevent the French side from building any rhythm.

As England found out in the Six Nations earlier this year, allowing Sheehan to have an inch of space to run into is very dangerous, and he is not the type of player who wastes opportunities when gaps do open up in front of him.

Jack Willis (Toulouse)

With Leinster possessing so much quality in their forward pack, it is likely that their meeting with Toulouse will be decided by who dominates the breakdown, with both sets of players likely to scrap for the ball in order to prevent their opponents from stringing together phases of passing as they hunt for a weakness in the opposing line.

With that in mind, the French side will be pleased to have one of the best jacklers in the world in their ranks, with England’s Jack Willis joining them after the demise of Wasps earlier this season and quickly establishing himself as a dependable option in the back row who can attack and defend with equal quality.

Leinster do have some ferocious ball-carriers in their side, but, once the ball hits the ground, Willis should be more than a match for them with his speed at securing turnovers, and it could be an interesting area of the game to keep an eye on.

Tawera Kerr-Barlow (La Rochelle)

Defending champions La Rochelle are France’s second hope of securing another Champions Cup triumph, and Ronan O’Gara’s team are undoubtedly one of the most feared sides on the planet in current times. When they are in form, as they have been throughout this year’s European competition, they are a really difficult team to stop, and can be likened to a rampaging animal that throws aside everything in its path.

The key to unlocking the power of their forwards and the trickery and pace of their backs will be in the middle, with scrum-half Tawera Kerr-Barlow a player to really keep an eye on as La Rochelle try to control the pace of the match. Time and time again, the former New Zealand half-back has demonstrated his decisiveness at the breakdown, his range of passing and the variety of his individual play, with him capable of finding a teammate or making a quick sniping run if there is a chance to do so.

Therefore, limiting his options will be essential if Exeter Chiefs are to have any hope of keeping the French giants quiet and edging past them into the final.

Henry Slade (Exeter Chiefs)

That aforementioned attacking threat that La Rochelle will bring to their semi-final means that Exeter will need to be strong out of possession and dominant when making tackle attempts. Normally, the full-back would be the key person to look at with this, but, with Tom Wyatt an inexperienced player who is still learning his trade at this level, the onus for organising the defensive effort will likely fall on England star Henry Slade, who is starting at 13.

This is not a bad thing, with Slade demonstrating his pace and ability to make quick recoveries and last minute tackles when needed throughout his club and international career, and he will be an effective player to have on the field when La Rochelle do make breaks up the field.

However, he does have a tendency to make mistakes at times and to give away needless penalties, and, if the Chiefs are to have any chance of stopping La Rochelle from taking them apart, as they have done with so many of their opponents in the last few campaigns, then these will need to be eradicated or at the very least kept to a minimum.