Manchester United are facing an uphill battle to qualify for the knockout stages of the Champions League after drawing at home to PSV Eindhoven in the last round of fixtures.
Louis van Gaal's team sit second in Group B with eight points, one fewer than Wolfsburg and one more than PSV.
United travel to Germany on Tuesday night to face a Wolfsburg team that caused them problems at Old Trafford in September, although the home side eventually won 2-1.
A win would guarantee Van Gaal's team, without a victory in their last three, a top place finish in the Group.
Failing to win makes things rather more complicated and takes their destiny out of their own hands.
A draw would mean that United can only finish second in the group and will be relying on bottom side CSKA Moscow to get a win in the Netherlands.
If United draw and PSV win then Van Gaal's side will ended up in the Europa League. If United draw and PSV also draw then United would still end up in the Europa League as head-to-head records trump goal difference.
United lost 2-1 to PSV in September, in the game that Luke Shaw suffered his horrific injury.
If Van Gaal's team lose then they can still qualify for the knockout stages, but only if CSKA win.
CSKA's only win in five matches of Group B came at home to PSV in September.
Wolfsburg have slumped in form recently, winning just three of their last eight matches in all competitions. However, they have been particularly strong at the Volkswagen Arena, going 29 matches unbeaten in all competitions before losing to Borussia Dortmund there on Saturday.
Van Gaal will also be without a number of options because of a growing injury list.
Morgan Schneiderlin and Wayne Rooney will be on the sidelines along with Ander Herrera, Phil Jones, Marcos Rojo, Antonio Valencia and Shaw.
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