The match kicks off at 17:30 GMT on Sunday at Ashton Gate and Lam acknowledged the timing was “not the best” for fans who want to attend.
Yet he said the home supporters can be the ones to make a difference as the team looks to bolster its chances of finishing in the top four of their pool of six, before facing Bulls away and Bordeaux at home in January.
Lam also pointed to the fact that all three of the away teams in the opening group round – Bristol, Northampton and Bordeaux – won, which gives them all an advantage this weekend as they play at home.
“If we all win our home games that’s going to put us in a great place as far as [finishing in the] top four in that pool of six,” he said.
“That’s the challenge and that’s what we’ve got to work for and we can only focus on getting our performance right. If we do that, there could be some really good rewards.”
Lam added: “This is all part of the process to get to where everyone thinks Champions Cup rugby is good, finals rugby, and we haven’t been there for a while and we want to get there.”
