Mutual history binds Munster and Gloucester together and the South African influences at both clubs mean there is plenty of familiarity across the divide this week.
The Irish province go to Kingsholm top of Pool B in this season's Champions Cup but with just four points separating the four teams vying for a quarter-final place, there is no margin for error.
Connections are everywhere. Gerbrandt Grobler spent last season at Thomond Park, while Munster defence coach JP Ferreira helped Gloucester coach Johann Ackermann guide the Johannesburg-based Lions to the final of Super Rugby in successive seasons.
While an assistant coach at the Springboks, Johann van Graan spent time working behind the scenes with the former Springbok whose son, Ruan, is one of a host of South Africans on the Cherry and Whites' books.
As well as Grobler, Van Graan coached lock Franco Mostert with the 'Boks, while full-back Mike Haley spent three seasons playing alongside Danny Cipriani at Sale.
Throw in the presence of former Ulster and Ireland players David Humphries and Jonathan Bell on the Gloucester staff and there is plenty of intel on both sides.
"It will be interesting," Van Graan conceded.
"When you see certain things that Gloucester do, you don't have to look (hard) to see it looks like things that other teams that guys have been involved with.
"I'm sure the opposite will be the same (with Munster). I think both teams will look at their own strengths, look at what they are currently doing well.
"I guess there are one or two moments in each game when you've got to roll the dice and when the opposition rolls the dice and I guess it's who reacts the best to that situation."
With inside knowledge on both sides and the game being played on a tight pitch in an intimidating ground, it should be a close contest.
The first game between the sides was turned upside down by Cipriani's red card for a high tackle on Rory Scannell, but Gloucester were dogged in the way they hung in the game with 14 men and although they left with nothing, they showed they had it within them to trouble Munster.
The Reds might have been home and dry by now had they not slipped up in Castres and playing first on Friday means they have the opportunity to either pull clear of their pool rivals or open the door further for Exeter and Castres who meet at Sandy Park on Sunday.
"There's no eyes on Exeter at this stage, only Gloucester," Van Graan (below) said of the sold-out decider at Thomond.
"This is knock-out rugby in Europe. We're in a good position with the fact we've got four points on Gloucester and Exeter, but only three on Castres. Castres play against Exeter so we've got to run our own race.
"I learned this last year in our game against Racing (92). Even though we lost the game, we picked up that bonus point. I think we lost 34-30 and that we took that point into the last round, got five points in the last round and that put us through for a home quarter-final.
"So just only worry about Friday night and follow our process through the week, prepare ourselves mentally and physically for a massive battle.
"There's no lack of motivation or excitement for this week. I think the key from the coaching point of view is to actually hold them back and not to waste unnecessary energy before we take the field on Friday night."
Van Graan is hoping the high stakes bring out the best in his charges who put together their most impressive 80 minutes of the season against Connacht on Saturday.
"This is a game all teams love to play in, and that's why you play in Europe, for these opportunities.
"Bar maybe two pools, all pools are so evenly poised and it's literally on a knife-edge, both ways," he said.
"Our pool, the fact that we lost the away one to Castres, brought two other teams into it and now over the next two weekends it's which one of those four teams play the best within the 80 minutes.
"That's exciting and if you're in rugby and in sport you have to embrace these moments. You can't inspire out of fear. We've got to inspire ourselves.
"I've never been to that stadium before but what I've read and what I've heard, it's an incredible place.
"It's a sell-out and it's Munster versus Gloucester. There's so much history between the clubs so it will be a fantastic rugby occasion on Friday night.
"I've said it so many times before, that's why I came to the northern hemisphere, for days like Friday evening.
"You've got the best players in both leagues that are going to go for each other and the winner over the next two weeks between the four teams, there's a quarter-final spot available so we have to look forward to it."
Subscribe to The Left Wing, Independent.ie's Rugby podcast, with Luke Fitzgerald and Will Slattery for the best discussion and analysis each week. From in depth interviews with some of Irish rugby's biggest stars to unmatched insights into the provinces and the national team, The Left Wing has all your rugby needs covered.