Harlequins boss Conor O'Shea says his team will have play with pace if they want to do the Heineken Cup double over Racing Metro this weekend.
Quins stunned the French giants 32-8 last weekend in Nantes, and they meet again this weekend at the Stoop.
O'Shea says the size and physicality of the Racing pack will dictate their own tactics - keep the ball moving at pace and avoid a set-piece arm-wrestle.
"We needed to win or we were about out of the competition," he told Sky Sports News.
"The last thing that happened - and we told the players after the match - was Mike Brown tackling Jonny Sexton into touch and that's half-time. It's a bit strange playing back-to-back games against the same team.
"But it's a big challenge and we know if we can do a job at the Stoop then we've got a huge game against Clermont Auvergne in January. It's great just to be in the mix because we had a difficult start to the season.
"But in the last couple of weeks we've come back in the Premiership and now the Heineken. We played excellently, with a huge amount of intensity. We need to start this match with the same amount of intensity.
"We have to move the ball around with pace. It if becomes a set-piece game then it becomes more suited to them.
"Although both our scrum and line-out were excellent, they (the Racing pack) are massive. I think when people come along to the Stoop and see them run out, live, they will see what challenge our players face.
"We have to keep the tempo up because if you go toe-to-toe with a heavyweight and you are a light-weight you are going to get beaten. We have to keep the ball on the move."
British & Irish Lions centre Jamie Roberts could return to the Racing line-up this weekend after three months out with injury.
"They have threats in some many places - Jamie is another massive bloke. They could have Jonny Sexton playing 10, Mike Phillips at nine, Dan Lydiate on the flank... they have so many good players. That is four from the Lions side which started the third Test (against Australia)," O'Shea added.
"But we've got some experienced guys, Nick Easter, Nick Evans, Chris Robshaw, Mike Brown, leading from the front. We've got some young English guys stepping up in recent weeks like Will Collier, Charlie Matthews and Charlie Walker - they will all start this weekend.
"That is great for the future of our club that these players are playing the top sides in Europe and that's why we love the Heineken Cup."