In just under two weeks, Munster will get their European Rugby Champions Cup campaign when they visit Castres in their opening pool fixture.

But before that, there is the small matter of a Guinness Pro 14 clash against rivals Leinster on Saturday at Aviva Stadium where bragging rights will be there to play for.

"It's always a big day out for both teams. There's a huge amount of rivalry - a healthy rivalry," Munster captain Peter O'Mahony told Oisin Langan at the launch of the Champions Cup at Convention Centre, Dublin.

"It's always massive intensity and you're playing against good friends and international team-mates, it's always nice to have one up on them for a few months. 

Munster's Peter O'Mahony ©INPHO/Dan Sheridan

"It's a great game for us to lead into Europe, with the intensity and the physicality and quality of opposition you play against Leinster, you know, no better team to get stuck into and for them to get stuck into us and have us both firing nicely for Europe."

He feels the fixture will help Munster get more "match fit" with key internationals and Lions returning to the fold after being rested in the early weeks of the Pro 14.

And given the test that awaits with a trip to France in the opening Champions Cup weekend, Munster need to tune up. 

"It's always difficult to play away in France," O'Mahony said of Castres.

"You know a team as good as Castres, the way they are playing, they beat Clermont last weekend. It's always a difficult place to go and play. They've a huge amount of tradition with this competition and a hugely proud club so it's always difficult."

Oisin also chatted to Munster director of rugby Rassie Erasmus... 

Erasmus and the coaching team have been keen to keep the players fresh.

"We're going to lose some games by doing that but hopefully we don't lose too many," he said.