"I came over here last week to look at the stadium and it is an amazing place,” Cullen said, before adding: “I’m glad we’re not playing Munster because it is very red out there."

Yet there are considerable parallels between the squad Cullen will send out into the San Mames today and the Athletic Bilbao team that calls this 53,289-capacity arena home.

Athletic have a rich history in Spanish football, winning La Liga eight times, most recently in 1983-84, and is owned and operated by members who have maintained a selection philosophy of Cantera, playing only players it considers as Basque or Basque heritage.

Leinster have reached today’s final drawing on mostly home-grown players themselves, their matchday squad of 23 featuring 20 Irish internationals, 17 of whom were born in the province.

Cullen said he saw today’s meeting with Parisian side Racing as a contest between two clubs with very different approaches to player recruitment.

“What Racing have built in the last seven, eight or nine years and what they have done in bringing in an expensive bunch of players … we have to do things slightly differently in Leinster where we produce guys from within, mainly.

We bring in a couple of key signings from overseas so it is a clash of styles in how you assemble a squad.

“The players are pretty excited being out there today. They understand some of the traditions with the club as well.

“Very similar to ourselves in that we base a lot of things on homegrown players.

“It is a fantastic setting so hopefully, we will get a good crowd of supporters to the city today and tomorrow.”

This story first appeared in the Irish Examiner.