Record and knockout berth on the line as Saracens travel to Wales
Holders Saracens will claim a European Champions Cup quarter-final place and new tournament record if they beat the Scarlets in Llanelli on Sunday.
Saracens rugby director Mark McCall has described the Pool Three clash as "a massive game" against opponents that beat three-times European champions Toulon last month.
Saracens host Toulon next week, but McCall knows his players can take that game out of the equation by winning at Parc-y-Scarlets and securing a European record 14 successive victories.
McCall's men are unbeaten in the tournament since losing to semi-final opponents Clermont Auvergne in April 2015, and more success would see them move ahead of Munster after the Irish province posted 13 straight European wins between 2005 and 2007.
Saracens have toppled five former European champions during their unbeaten run - Toulouse, Toulon, Wasps, Northampton and Ulster - and McCall wants to make it a case of job done this weekend with regard to the quarter-finals.
"I think they (Scarlets) lost their very first home game of the season, and then have won eight consecutively," McCall said.
"It is a tough old place to go. They have got some big scalps there.
"It is a game with a lot riding on it for us. It is a massive game."
One of the players aiming to plot Saracens' downfall will be Wales international back Liam Williams, whose move from Scarlets to the reigning English and European champions next season was confirmed just four days ago.
"It is an exciting signing for the club," McCall added. "For now, he plays for them, and we have got a big job to do.
"He is a magnificent aerial player, he is superb, whether under a high ball or chasing a high ball.
"He is elusive, he's quick, he's aggressive, he is a good defender. He is everything you want in a winger."
Should Saracens lose - and Toulon beat Sale Sharks in France on Sunday - then the group will go down to next week's final games, but McCall's team look well set to progress after claiming 18 points from a possible 20 so far.
"It has been a good campaign for us so far - 18 points from the first four games took a lot of doing," McCall said.
"But we understand the importance and the significance of this game in terms of getting us what we want, which is a home quarter-final."
Fly-half Owen Farrell will captain Saracens in the absence of a suspended Brad Barritt, whose place in midfield is taken by Nick Tompkins. Elsewhere, wing Chris Ashton returns to the starting line-up, but an ankle injury sidelines Alex Goode, so Alex Lozowski features at full-back.
Leicester's hopes of progressing from Pool One will end if they lose to Racing 92 in Paris on Saturday, but a bonus-point victory over last season's Champions Cup runners-up - followed by another five-point maximum at home to Glasgow - could see them march on.
It is a tall order for the Tigers, but encouraging displays in their last two Aviva Premiership games against Saracens and Wasps suggest it might not prove beyond them.
"In the past two weeks we've played the top two teams in the competition, and we've shown in both weeks that we are not far off," Leicester head coach Aaron Mauger said.
"We will take a lot of belief out of that."
Munster will win the Tigers' group if they beat Glasgow at Scotstoun on Saturday, but Leicester's east midlands rivals Northampton are consigned to an early exit, propping up Pool Four heading into their Franklin's Gardens appointment with Castres.
Saints rugby director Jim Mallinder has made three changes for the game, with Juan Pablo Estelles replacing Jamie Elliott, Jamie Gibson taking over from Louis Picamoles and Harry Mallinder starting in midfield instead of JJ Hanrahan.
Sunday's Pool Three programme apart, there are two games in Pool Five, with French heavyweights Clermont Auvergne guaranteed a quarter-final place if they beat Bordeaux-Begles, while Exeter meet Ulster at Sandy Park.