Leicester, the 2001 and 2002 European champions, cannot realistically afford a second Pool Six loss following an opening weekend reversal against Leinster.
And although Tigers beat Toulouse 14-9 at Welford Road last Saturday, their opponents showed enough quality in dreadful conditions to suggest the return encounter could be a completely different story.
"Toulouse are a world-class team," acknowledged Leicester assistant coach Richard Cockerill.
"They are certainly one of the teams who can win this tournament, and they are a better side than they were last year.
"We will take heart from the win last Saturday, but we also class ourselves as one of the big teams, and we should have been better.
"We need to win all our games - second is not going to be good enough in this group - and to win in Toulouse, we will need to do everything right and stop them playing."
Leicester boss Marcelo Loffreda has made several changes, including recalls for England World Cup forwards George Chuter, Ben Kay and Lewis Moody, together with Irish international Geordan Murphy, who starts at full-back.
All Blacks centre Aaron Mauger though, who looked well short of match sharpness on his debut last weekend, drops to the bench as Ollie Smith and Dan Hipkiss forge Tigers' midfield partnership.