Three months on and the two sides will go at it again with qualification for the knockout stages on the line in this Pool 2 finale as the English Premiership-leading Chiefs visit Thomond Park for the first time on Saturday evening with a mission to upset the odds.

Not only would Rob Baxter’s side be the first team to qualify for the quarter-finals having failed to win their first three pool games, they would have to do so by becoming just the fifth team in the history of the competition to have won at Thomond Park and, in the process, deny Munster a losing bonus-point in order to top the group.

Kleyn knows exactly how hard-fought this return fixture will be and the lock said: “It’s going to be a massive battle. There is a lot on the line for both teams.

Obviously, we want to keep on our winning ways. It is going to be a real attritional battle. The game at Sandy Park was 80 minutes of hell and I expect this weekend to be the very same.

Asked about his vivid description of that opening game the 25-year-old second-row admitted: “Yeah, hell is a strong word, but it is going to be tough, man.

“It was real tough over in Sandy Park with the conditions, which probably didn’t help. The first-half we were playing against a really strong headwind so there were a lot of one-metre carries, a lot of really hard tackles and stuff. They have a really strong pack but they carry hard and they defend hard as well. So it is going to be hard on the bodies and I expect a lot of boys will be coming in bruised on Monday morning.”

You can be sure those bruises will be a lot less painful if there is an 18th quarter-final in the province’s history to target at the end of March and given Munster’s schedule of late, going from European rounds three and four into three interprovincial derbies in the PRO14 and then back into Champions Cup rugby last weekend with a bonus-point win at Gloucester. As important as all those were, the knockout element of Saturday’s final pool game makes the visit of Exeter the biggest game of the season so far.

“I say that but then last weekend was the biggest game of the season and the weekend before that was the biggest, so we are at a point in the competition where nobody can let anything slip, just because of the points margins as well.

“We pick up a bonus point and we end up one position higher than we would have, don’t pick up a bonus point and we are one position lower. So it is really at a point in the competition where no-one can miss a step. It is getting to knockout stages now at this stage. You want that home quarter-final, that home semi-final. It is real tough, difficult.

“That is one of the points we set out for ourselves, to have a home quarter in the PRO14 and the European Cup and we are on track for both, but we have to keep pushing ahead.”