Wolfsburg star Andre Schurrle has admitted that it is "surprising" that Manchester United are currently struggling for goals.
Schurrle can help guide Wolfsburg to the last 16 of the Champions League for the first time if they earn at least a draw against United in Germany this week.
United, who have scored just one goal in their last three games, need to win if they are to reach the knockout stages of the elite competition.
"It's surprising that they are struggling to score goals, but they have amazing players and they know where the goal is, so we've got to be very careful," Schurrle told reporters.
"When you speak about United, you speak about a big club and you know they have great players. We know we will get chances, and if we convert our opportunities we can have a great game against a great club."
United are second in Group B, one point adrift of Wolfsburg and just one ahead of PSV Eindhoven.