Toulon edged the Welsh outfit at Stade Felix Mayol 21-20 last October but when they met at Parc Y Scarlets last January, the hosts were victorious by three points, 30-27.

Little wonder then that flanker O’Donnell considers Saturday’s game such a key fixture in Munster’s season.

“The main thing is to bounce back from Edinburgh,” he said. “Scarlets are one of the best teams in the league and you have to up your performance for them. It’s a home game and that’s a good thing as you can rely on and use the familiarity of Thomond Park. The cherry is that if you get a good performance this week, you’re building into a very important game next week which tees up your whole season.

“You’ll have a very busy schedule heading into the end of the season if next week goes well... you just have to make sure we get through it with a convincing performance and start nailing off on our detail and build on it the week after.

“I know it’s easy to look forward to a quarter-final but when you’re looking at a good team like Scarlets in front of you, you have to deal with them first and approach them with every bit of sincerity and due diligence because they are such a good team.

“They can score from anywhere as we saw with them in the two games last season. We’ll have to be on the ball to deal with them and then worry about next week when it becomes next Monday.”

Only too well aware of the two cracking matches already this season between Scarlets and Toulon, O’Donnell observed: “Scarlets can give us a kind of blueprint of how we need to play against Toulon. And we’ll get a good idea of what it takes to beat Toulon if we play well against Scarlets.”

There is considerable relief in the Munster camp that O’Donnell is back to full fitness having missed much of the season with torn AC ligaments.

His importance to the Munster cause is all the greater now that Chris Cloete, the South African who was challenging him for the No. 7 jersey, is out for the remainder of the season with a broken arm.

“I’m fit and well and it’s good to be back and travelling with the lads having been out for the bones of three months,” he said.

“There is never a great time to get injured. If it happens early in the season, you’re going to miss the autumn internationals, if you get injured in the middle of the season, you might miss the Six Nations.

“The positive thing is that I was able to come back towards the tail end of the season. That’s what I’m looking forward to now, a good run of form towards the end of the season. I tore ligaments in the AC joint, a tricky one because when it comes to the physical part of rugby, you need your shoulder to be fully able to take the contacts and the hits and it’s back to that point now.”

Johann van Graan gave the air of a man this week who wasn’t unduly perturbed at the manner of last week’s loss to Edinburgh although you can also only assume there was some straight talking at the review meeting on Monday morning.

“It was frustrating that we weren’t as clinical as we needed to be,” O’Donnell accepted.

“In fairness to Edinburgh, they have lost only once at home, they’re tough, they turned us over at the breakdown, they slowed us down, frustrated us and took their two chances.”