The eight sides already through to the Europa League knock out stages could be joined by several more this week if the fixture list withstands the freezing conditions sweeping northern Europe.
Manchester City and Lech Poznan can progress from Group A when they host Salzburg and Juventus today, but with snow and icy conditions forecast it is far from sure that all this week’s 24 games will go ahead.
Sporting Lisbon should have no such problems when they aim to clinch the point they need against Lille to join Zenit St. Petersburg, Stuttgart, CSKA Moscow, BATE Borisov and FC Porto in the next round.
Spartak Moscow, FC Twente and Rangers will be among the eight sides to drop into the tournament from the Champions League.
Like Lech Poznan, Manchester City will be sure of a place in the next match if they win. Last-place Salzburg must win their two remaining matches to have any chance of qualifying, with any other result eliminating the Austrian champion.
“We have to believe in our chances,” Salzburg coach Huub Stevens said. “But we should also be realistic. Manchester City and Juventus are the two favourites in our group.”
Not least with Salzburg traveling to England without five injured players and a crucial domestic league game with Austria Vienna scheduled for Saturday.
“We will give everything against Man City today,” Stevens said. “But we’ll be looking forward to Saturday as well because we surely need a fresh team then.”
City have won just two of their past eight matches, but winger David Silva said a 3-1 loss to Lech Poznan did not reflect their strong performance.
“European games are more strategic, almost like games of chess,” Silva said.
“But I think we’re doing OK so far. If it was not for the bad luck we encountered in the last game, we would probably be on top of the group. We’re not far away, and it’s in our hands to do well.”
Juventus will be out of contention if they stumble in Poland. Armand Traore and Simone Pepe are likely to be used as emergency fullbacks for the Italian giant.
Traore is expected to fill at leftback with Fabio Grosso and Paolo De Ceglie unavailable, while Pepe is one of two options coach Luigi Delneri has to replace injured duo of Marco Motta and Zdenek Grygera, and the ineligible Frederick Sorenson.
The alternative is to move Leonardo Bonucci from the centre of defense.
Juventus are on a run of 13 games without loss in all competitions made up of five wins and eight draws.
Group B leaders Bayer Leverkusen can qualify with a win at Rosenborg in another of today’s 12 matches, but any other result could leave the German side needing a positive result against defending champions Atletico Madrid in the final round of group matches.
Atletico could already be through by then if they beat Aris today.
Odense and Getafe both need to win their meeting in cold and snowy Denmark to stand any chance of advancing behind Stuttgart in Group H, but the home side is coming off a poor 2-0 home defeat by Brondby.