The former Ireland lock has vast experience in the European Cup, making 92 appearances in the competition as he helped Leinster to three titles as a player, before guiding them to a fourth as head coach in 2018.

Although Leinster opened their 2021/22 campaign with a convincing 45-20 win over Bath Rugby on Saturday, Cullen believes that the task facing his side as they gun for a record-equalling fifth triumph this season is going to be tougher than ever.

“It’s an incredibly hard tournament to win and you want to go all out to try and win it,” he said. "A lot of teams are gearing up and [have] signed players. [There’s] a ton of experience in some teams very close to here; they’ve spent big. Lots of teams in Europe are spending big.

“So, we need to make sure we understand some of the threats. It’s not just us, we have our own motivation, but everyone has their motivation.

“What are you prepared to do when it comes down to it on the day? So, that’s the bit people need to get right. But that’s the exciting part, working hard and trying to deliver on the biggest days.”

Despite Leinster’s target of securing the trophy once again, Cullen urged his side to first concentrate on navigating their pool games before considering potential knockout stage opponents.

“The play-off games are miles away – you’ve got to get there first,” he stated. “So, in many ways, with the competition format, it feels like it’s knockout rugby from the very, very start.

“It’s not quite knockout rugby, but it’s not far off it. Similar to that last-16, home-and-away dynamic, it’s a different dynamic for us to get our head around.

“Will it help us or hinder us? I don’t know. We need to focus on these games to try and find that fact out.”

Leinster Rugby head coach Leo Cullen has highlighted the strength of the teams competing in this season’s Heineken Champions Cup, acknowledging that a lot of things must click into place to lift the trophy.