This is the kind of night that the Munster legend was built on. Away from home in a traditional English stadium, under Friday night lights and with their backs to the wall, the team of 2019 must perform or risk elimination.
Pool 2 is as tight as it can be. Four points separate the teams and the Irish province are on top but remain vulnerable.
A lot can change in the last two rounds but as it stands it seems unlikely that two teams will emerge from this quartet.
Exeter and Castres will be watching closely and hoping for a Gloucester win ahead of their own clash on Sunday. Across their vast history in this competition, Munster have rarely been in such a competitive group.
With all of that going on, it is easy to forget that they are on top of the pool and not relying on any favours.
Win at Gloucester and they go into next week's already-sold-out home game against Exeter Chiefs with a cushion.
It is a simple equation and they have spoken all week of the cup-rugby nature of it all. It is bread and butter to a team of their experience.
They will know that they should be in a more comfortable position but the only thing they can now do about their disappointing defeat in Castres before Christmas is learn from it.
By selecting three second-rows in his starting pack, Gloucester coach Johan Ackermann is clearly going after the visiting side up front and in particular at the lineout.
Munster's maul was successful against Connacht last weekend and all of their good play flowed from there.
The four-try win at the Sportsground was Van Graan's side's most complete of the season in that they controlled the game from start to finish.
Their defensive work was not where they wanted it to be and needs to improve but if they can pick their options as well as they did in Galway they'll be on their way.
Slowly but surely Gloucester are returning to the status they once held as a force to be reckoned with.
With former Ireland out-half David Humphreys in charge of the long-term planning and Ackermann running the show on the pitch, they've struck a good balance.
The recruitment of Danny Cipriani has been a coup and his red card in Thomond Park skewed what might have been a closer game.
He returns from injury just in time to face Munster who have a like-minded figure in their own No 10 shirt - Joey Carbery, who has the rugby world at his feet just like Cipriani did a decade ago.
That the two men have the same number of international caps (16) despite the eight years between them speaks volumes for the way the Englishman has veered off course.
But he has the capacity to break games wide open and when on song, is a quality out-half.
The playmakers can only thrive on the ball they are given but Munster's improving pack will be confident of winning the physical exchanges despite Chris Cloete's injury keeping him out for another week.
The powerful presence of Chris Farrell in midfield offers even more grunt when needed, but Gloucester won't be found wanting in that department.
The controversial Gerbrandt Grobler could have a big influence on proceedings.
The powerful lock, who like his coach Ackermann served a two-year doping ban after a positive test for steroids, spent last year at Munster and knows their set-piece and game-plan.
Munster have their own weapon in defence coach JP Ferreira who worked with Ackermann at the Lions in South Africa and if the intel all checks out then it could be a tight affair full of second-guessing.
For all that Kingsholm is an intimidating place to go and Gloucester are a rising force, Munster have been to the last four of this competition twice in a row and possess a lot more quality players than their opponents.
They need their Ireland stars to take control of the game, with Peter O'Mahony, Conor Murray, Keith Earls and CJ Stander central to what they do.
Niall Scannell's throw will be under pressure, but if Tadhg Beirne finds the right variation in his calling then they can stay ahead of the home side out of touch.
Ultimately, Munster need to take their chances. Carbery has bounced back from the missed kicks in France, while the attacking game showed signs of clicking against Connacht.
They are contenders for this tournament, but they must get out of the pool to prove their credentials. Tonight is the night.
GLOUCESTER - T Hudson; C Sharples, B Twelvetrees, M Atkinson, O Thorley; D Cipriani, C Braley; J Hohneck, H Walker, F Balmain; E Slater, G Grobler; F Mostert, L Ludlow, B Morgan (capt). Reps: F Marais, A Seville, C Knight, F Clarke, G Evans, B Vellacott, O Williams, H Trinder.
MUNSTER - M Haley; A Conway, C Farrell, R Scannell, K Earls; J Carbery, C Murray; D Kilcoyne, N Scannell, S Archer; J Kleyn, T Beirne; P O'Mahony (capt), T O'Donnell, CJ Stander. Reps: R Marshall, J Loughman, J Ryan, B Holland, A Botha, A Mathewson, T Bleyendaal, D Goggin.
Ref - R Poite (France).