The European Champions Cup competition moves up a gear with some pivotal pool clashes this weekend

Three of England’s heavyweight challengers will be without key international players when they face testing European Champions Cup clashes this weekend.

Saracens and England star Maro Itoje will miss his club’s European clash against Clermont Auvergne on Saturday (Paul Harding/PA Wire)

Saracens have lost broken jaw victim Maro Itoje ahead of Sunday’s Allianz Park clash against Pool Two rivals Clermont Auvergne, while Leicester tackle Munster in Limerick on Saturday minus England prop Ellis Genge, who faces shoulder surgery.

And a third England international – Bath wing Semesa Rokoduguni – is also on the sidelines, awaiting a shoulder operation and missing his club’s key Pool Five encounter against Toulon at Stade Felix-Mayol on Saturday.

The trio could face a race against time to be fit for England’s opening NatWest 6 Nations appointments with Italy and Wales in early February, with Bath confirming Rokoduguni as a latest addition to Red Rose boss Eddie Jones’ casualty list.

We'd obviously like to wish @rocco3225 all the best in his recovery 🔵⚫️⚪️ — Bath Rugby (@bathrugby) December 8, 2017

“One player who is not available is ‘Roko’ (Semesa Rokoduguni), who will be going in for surgery on a shoulder injury sustained against Exeter (last Saturday),” Bath rugby director Todd Blackadder said.

“It’s obviously a big loss, but we have the likes of Matt Banahan and Aled Brew, among others, who can really cause the Toulon defence problems on Saturday.”

Victory for Bath would keep them top of their group prior to Toulon’s Recreation Ground visit next weekend, while Leicester will be in a similar position if they triumph at Thomond Park, with Pool Four shaping up as the tightest Champions Cup group this term.

“We lost some key blokes for a month in the autumn Tests and got them back together in bits and pieces, and now it is about trying to get that continuity back,” said Leicester head coach Matt O’Connor, whose returning players include England wing Jonny May.

“Playing against Munster at Thomond Park is one of the great joys in European rugby. It is a special place in the European game.”

Elsewhere on Saturday, the Scarlets welcome back seven Wales internationals in their starting XV following autumn Test commitments for a home clash against Benetton, with Northampton and the Ospreys – cut adrift behind Saracens and Clermont in Pool Two – meeting at Franklin’s Gardens.

Saracens know a home win against Clermont, the side they beat in last season’s Champions Cup final, is vital, but they go into battle following five successive Aviva Premiership and Anglo-Welsh Cup defeats.

“Over the last few weeks we have talked about many things internally, but the one that stands out for me is the importance of how a collective and joined-up effort will be for us over the next few games,” Saracens captain Brad Barritt told the club’s official website.

Also on Sunday, Premiership champions Exeter host Pool Three leaders Leinster, while Wasps go to Pool One top dogs La Rochelle, with the French club, Leinster and Saracens the only teams boasting a maximum 10 points from two games.

Assessing the Leinster test, Exeter rugby director Rob Baxter said: “It’s a very big game, but it’s a big game because we have won our last two pool games and we are right up there.

“I am genuinely looking forward to seeing how we deal with the pressure of being towards the top of the Premiership and doing well in our pool.

“For all of us, Sunday is not just a game to enjoy, it’s something for us to go out and win.”