The Warriors gave away nineteen penalties, a penalty try and received two yellow cards in the 35-30 win over Cardiff at the Arms Park and Grayson Hart says they can't afford a repeat show in France.
Speaking in the Scotsman, Grayson said.“With that discipline it would be tough to get a result. We made errors and put ourselves under pressure. Racing 92 are a pretty classy outfit. You never know in rugby but against opposition like that it will be tough to get the win if we put ourselves under that much pressure."
Tries from Leone Nakarawa, Taqele Naiyaravoro, Ryan Grant and Jonny Gray should have been enough for a comfortable win in Cardiff but, thanks to a string of penalties, the Warriors were left hanging on at the end.
Grayson added: “We did do really well when we built a lot of phases near their try line, though. We put them under a lot of pressure and came away with the results most times we were down there so that is something we need to keep building on. Definitely a lot of positives.
“For the last 25 minutes, I was in the crowd watching and was a very nervous spectator. The momentum had a couple of changes in that second half and then the last five minutes or so was nerve-wracking.”