Statistics strongly favour the French champions and league leaders in the knockout round second leg tie - no team have come back from a 0-3 home defeat to qualify for the next round of the European Cup.
Lyon seemed serene a week ago, having lost only three games since the season's start, one in the Champions League against Manchester United and two against Lille in domestic competition.
Since then, however, their momentum has been checked by a shock elimination from the French Cup by second division Clermont and a 1-0 defeat at Caen on Friday.
A hectic schedule of seven games in 23 days has taken its toll in terms of injuries as Lyon lost defenders Claudio Cacapa and Anthony Reveillere as well as captain and striker Sidney Govou.
Govou will be back for tonight's game but Reveillere is certainly out. A last minute decision will be made on Cacapa and the Lyon camp is clearly nervous.
"We worked so hard in the first leg that our one and only goal is to confirm our victory in the second," said striker Florent Malouda.
"We're only at the halfway mark and they're quite capable of scoring four goals away."
Werder Bremen's five-match winning run in the Bundesliga came to an end when they were beaten 1-0 by Bayern Munich on Saturday, a result that leaves them seven points off the pace.
Just as in the first leg at home to Lyon, it was their forwards who let them down, with Miroslav Klose and Nelson Valdez failing to take the chances that came their way.
"We've lost a crucial game and we're down because of it," said Valerien Ismael. "We have to be sharper in these big games."
Ivan Klasnic, who was forced out of the first leg after being injured in the warm-up, was absent from the Bayern game with a leg muscle strain and is doubtful.
Hungarian international midfielder Krisztian Lisztes is nearing recovery from a cruciate ligament injury and could be in the squad.
The good news for coach Thomas Schaaf is the return from suspension of captain Frank Baumann. He should slot back in at centre-back, with Ludovic Magnin moving forward to midfield.
: Coupet; Diatta, Cris, Essien, Abidal; Diarra, Pernambucano, Clement; Govou (captain), Wiltord, Malouda.
: Reinke; Pasanen, Baumann, Ismael, Stalteri; Magnin, Jensen, Ernst, Micoud; Valdez, Klose.
: Valentin Ivanov (Russia).