"December and January are when you really make your pitch for the rest of the season - and for us that starts on December 12," said Leinster coach Michael Cheika.
"The Scarlets are the leaders of the group and that puts them in a commanding position, while having the home leg of the back-to-back games against us first is a massive benefit to them.
"We are at the stage of the tournament where you stare at the opposition and make sure you don't blink first - this group looks as if it will be going down to the wire.
"All the Pool 6 matches are massive for all four of us and, as far as I am concerned, the only thing that matters is that on Saturday we perform at a level to get the win at the Scarlets.
"We are in a situation where we are missing a few guys but also pretty happy with the way we have developed."
Leinster were not alone as both teams had disappointing domestic weekends with the Scarlets losing 17-16 to Edinburgh in west Wales. But in the Heineken Cup the Scarlets are the ones who are two from two and Leinster one from two and Cheika admits: "We had a Round 1 loss against London Irish and that has put a bit of an edge on things.
"Of course we were unhappy with our defence against the Dragons but we had rested a lot of players and I don't think you will see that many of them in the matchday 23 on Saturday.
"However, after this disappointing defeat, we are obviously very eager to go and take on the Scarlets on Saturday and we will look at that as another game and, as after any loss, all you can do is get ready for the next challenge."
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