Atletico Madrid forward Adrian claims there is no danger of the Spaniards underestimating Celtic in their Europa League clash on Wednesday.
The Primera Liga outfit will travel to Glasgow in midweek looking to prolong their continental adventure.
Victory for Atletico at Parkhead will be enough to see them through to the knockout stage of the Europa League and possibly dash the Bhoys' dreams in the process, depending on results elsewhere.
Adrian insists Atletico will be going all out for the win on Scottish soil, but is aware that Neil Lennon's side will pose a considerable challenge in front of their own supporters.
"This match is important for us because we want to secure qualification in Europe this week," the former Spain U21 international told skysports.com.
"It was disappointing that my goal in the Bernabeu at the weekend (in a 4-1 derby defeat by arch-rivals Real Madrid) was not a winner, but that match is forgotten and we are focused on Celtic.
"If people believe that this match will be easy, they are very wrong. Celtic in Glasgow are very dangerous, especially as they need the points.
"The key to winning in Glasgow? To make the most of our spirit and to concentrate from the first minute. This is an opportunity for us to put down a marker to our rivals.
"There is a big difference between the Primera Liga and the SPL, but anything could happen in this match. We will have to work very hard.
"Our problem in the league has been inconsistency, but in Europe we have looked more compact and our defence has been difficult to break down.
"We now have to look to dominate and score the first goal against Celtic to break their spirit.
"There will be a magnificent atmosphere in Glasgow and it would be wonderful to score and to help pick up a win."