His side’s pursuit of a fifth European Cup ended with a 32-23 semi-final defeat at Stade Rochelais last season, which came after losses to Saracens in the two years previously – at the quarter-final stage in 2020 and in the 2019 final.

“Yeah, we’re gutted when we lose,” he admitted. “There are so many bits that go into the performance; we can control our own pieces that are here, but we can’t control some of these teams outside of here.

“The big thing is that we’re competing, we’re knocking on the door, and you’ve got to get to that stage.

“But that’s very end-of-the-road stuff there, what you’re talking about; it’s the in and out, and getting ready for ’Okay, well, we need to deliver now to get us to that situation’.

“So, we don’t make a big deal about the knockout piece. We’ve learnt some harsh lessons from some of the bits that we don’t quite nail and it’s [about] making sure you do nail all the bits.

“But for now, it’s [about] making sure that you’re trying to control what you can control.”

Leinster face Bath Rugby and Montpellier Hérault Rugby home and away in Pool A this season – both of which Cullen highlighted as tough places to visit that will require considered team selection.

“But then you have the other variables: opposition, what are we going to face? Montpellier [and] the challenge of going to France on a six-day turnaround,” he pointed out.

“Bath over in The Rec[reation] Ground, in January - I watched them last week against Exeter and the pitch is already starting to get heavy. It’s pretty renowned, where it’s located, beside the river - it gets wet.

“[You need to consider] the style of rugby that is [needed] when you’re over there [and] what type of team you need to play that style of rugby.

“So, there are so many different pieces that go into the selection. But the big thing is making sure our guys are fit and raring to go, giving them different opportunities at different stages, and that’s why some of our selections may be a little bit different to what other teams would do during the course of the season.”

Leinster Rugby head coach Leo Cullen has revealed that the Irish province’s recent heartbreak in the Heineken Champions Cup knockout stage has taught them “harsh lessons”.