Celtic defender Mark Wilson feels the pre-season victory in Porto proves a Champions League away win is possible. "I think everybody thought Aalborg were going to be easy to roll over but you won't roll over any teams in the Champions League.
"The boys knew that when the draw was made. When you are playing in the Champions League, teams are full of quality.
"But we can maybe pick up something away from home this season. In previous seasons it's been difficult for us but Porto in pre-season was very much like a Champions League game away from home, even though it was a friendly."
Wilson insists defeat against Villarreal would not effectively end their bid to make the knockout stages again.
He added: "We have been a bit unfortunate away from home, the Benfica game springs to mind where we suffered bad luck and ended up getting beat. A bit of luck wouldn't go amiss.
"After Villarreal we still have two remaining home games and Aalborg in Denmark. It's going to be difficult at Villarreal and Old Trafford, they are tough games, not just for ourselves, but for any team.
"We will be looking to pick up a point or three but if we don't, I don't think it's the end of the campaign by any means."