"There is a technique to passing and we didn't pass very well today in a lot of circumstances. In a very simplistic form, it cost us getting an extra try."

Three first-half penalties from Jonathan Sexton gave the home side a 9-0 lead, but both Shane Horgan and Luke Fitzgerald knocked on with the line at their mercy.

"I think we passed very poorly,” Cheika added. “There were some opportunities we created that needed a better pass out in front, a couple of balls went to ground and just finishing a little better, accuracy in that area.

"We know we could have made more of some of our opportunities. We dominated the possession and the game and sometimes it just didn't happen.”

An unexpected bonus point against Wasps last time out has Leinster favourites to progress from Pool Two, but Cheika knows to be cautious ahead of next week's trip to Castres.

After comprehensively beating Bourgoin at home in the 2005-06 tournament, they lost the away game.

"One thing we have tried to do this season is to take every match as a final,” Cheika added.

“No matter what happened today, extra point or not, we have to go down there and win next week. People maybe expected this while they didn't really expect the Wasps one.”

Castres sit in the relegation zone in the French Championship and forwards coach Jeremy Davidson says the emphasis for the club is staying in the top flight.

"Our main focus is the championship but we will look to build into the Perpignan game before Christmas. We won't want to go into the Perpignan game with a defeat," he said.

Leinster know their destiny is in their own hands and Cheika will look to the return of a number of key players for next week's game.

"We're hoping (Shane) Jennings, (Isa) Nacewa and (Felipe) Contepomi will be available,” he added. "That will be assessed on Monday. What that will do is give new energy into the squad and another healthy bite of competition.

"If I can get that situation and that scoreline in all the games we play in this tournament, I will be happy enough. It's about making sure we improve on those issues for next week."