Saracens loosehead prop Mako Vunipola has highlighted discipline as being vital when they take on Wasps in their Champions Cup semi-final.
Saturday's showdown at the Madejski Stadium in Reading will see two of Europe's best teams collide in what should be a high-pressure game.
And for Grand Slam winner Vunipola, he believes his team needs to improve on the discipline they showed against Harlequins last weekend.
"We're pleased with the result although we know there are things to clear up. Our discipline let us down a bit against Harlequins and that starts from me at scrum time," he told EPC Rugby ahead of the mouth-watering match.
"We'll go away and learn the lessons from that, but we know we will have to be a lot better when we play Wasps."
The winner of this game will progress to the Champions Cup final, against either Leicester or Racing 92, which will take place in Lyon.