Borussia Dortmund can keep alive their bid to return to the Champions League final for the second straight season with victory over Marseille at the Velodrome on Wednesday.
The Bundesliga side will reach the knockout stages next February by taking maximum points regardless of what happens in the second Group H fixture between Napoli and Arsenal in Italy.
Napoli, who are on nine points with Dortmund and three behind Arsenal, must beat the Premier League pacesetters by three clear goals, should Dortmund also win in France.
However it will be the German club who go through with Rafa Benitez's team due to their superior head-to-head record against both clubs.
Arsenal will go through with a draw or a defeat by two goals or less.
Marseille meanwhile are in turmoil, and fired coach Elie Baup following their 1-0 home defeat against Nantes on Friday, replacing him with Jose Anigo.
They cannot even dream of the consolation of Europa League football in the New Year as they are pointless following five straight defeats.
Dortmund coach Jurgen Klopp looked on as his side suffered their fourth league defeat of the season on Saturday when they slumped 1-0 at home to second-placed Bayer Leverkusen but the price was heavier than just three points.
Germany midfielder Sven Bender is ruled out after limping off with an ankle injury while Turkey international Nuri Sahin is doubtful after slightly tearing an ankle ligament.
"We lost 1-0, but that's actually the least of our problems," Klopp said following the match.
Dortmund are already withouth midfielder Ilkay Gundogan, defender Mats Hummels, Neven Subotic and Marcel Schmelzer as Klopp's injury worries show no sign of easing.
He is also down to his fourth choice at centre-back, having played Bender out of position in the 3-1 win over Napoli on matchday five, as Manuel Friedrich is cup-tied and Hummels injured.
"We now find ourselves in the situation where we are constantly having to react," said Klopp.
"But necessity is the mother of invention, so we'll see what happens.
"We have certainly had easier moments, but we have to fight on."
Caretaker manager Anigo takes charge of his first match back at the helm of Marseille after a four year spell between 2001 and 2005, preceded before then as sporting director.
The club, who are fifth in Ligue 1 and 13 points back of Paris Saint-Germain, parted ways with Baup following their sixth league defeat of the season on Friday.