Munster head coach Johann van Graan is ready for the “massive challenge” posed by defending champions Saracens on their home turf in the European Champions Cup clash on Saturday.

The Irish province claimed an edgy 10-3 win at a blustery Thomond Park last weekend but go to London in search of maximum points in a bid to keep pace with Pool Four leaders Racing 92.

"It's a massive challenge ahead," Van Graan told the tournament's official website.

"We are playing against the very best team in Europe currently. They've got so much quality within their squad and what they do.

"I think both teams couldn't really show everything they had on the weekend, because you only had 40 minutes to do what you wanted with ball in hand, just because of the conditions in the second half.

"A lot of times you can't say 'it doesn't get bigger than this', but in terms of European rugby, going to London on Saturday afternoon against Saracens, they're currently the best, so looking forward to seeing where we are."

Tighthead prop James Ryan returns for Munster to make his 150th appearance for the province, while Saracens will see full-back Max Malins and lock Joel Kpoku make their full European debuts.

Mako Vunipola and Jamie George return to the front row for Sarries alongside 2019 Rugby World Cup winner Vincent Koch.

*Glasgow Warriors winger Niko Matawalu is looking forward to running out in front of a packed Scotstoun once again this weekend.

Glasgow host La Rochelle and will look to back up last Saturday's 27-24 win in southwestern France.

"The boys are pumped up for this weekend," said Matawalu.

"We learned a lot from last weekend's games. We know there are a few things we can improve from last week and we've been working on them in training this week.

"Every home game we know that we're going to be tough to beat. The Scotstoun crowd is the best crowd in Europe, in my opinion. We know La Rochelle will be tough, but we're going out there to get the win."

Connacht welcome Gloucester in Pool Five while Montpellier play Toulouse in an all-French clash in the same group.

In Pool One, Leinster welcome Northampton without injured fly-half Johnny Sexton while Benetton host Lyon.

In the European Challenge Cup, Pool Two sees London Irish take on Toulon as they look to avenge the five-try 37-17 win in the south of France.

Scarlets host Bayonne in the same pool while Leicester will be looking for a double over Calvisano, who they thrashed 59-7 in a nine-try romp last weekend.

Adam Thompstone scored one of those tries at Welford Road but told his club's official website: "We're expecting a tough test when we go there. They've obviously got a point to prove from the weekend and we expect them to come out firing. We're expecting a tough challenge."

Bristol travel to Paris to take on Stade Francais keen to back up their 37-11 win over the French Top 14 side at Ashton Gate.

The Bears have made eight changes for the clash and are aiming to maintain their 100 per cent record in the competition.

Bristol director of rugby Pat Lam said: "We've had a fantastic start to the European Challenge Cup and we've made no secret of how important this competition is to us. Five points are on offer this weekend and that's the focus."

Saturday's other games see Wasps host Edinburgh and Bordeaux Begles take on Agen.