Villarreal defender Raul Albiol admits facing Atalanta is ‘more difficult than playing Inter, Juventus or Milan’ ahead of the Champions League showdown.
It kicks off in Bergamo on Wednesday at 20.00 GMT.
La Dea need a victory to reach the Round of 16 at the expense of Villarreal, while Manchester United have already qualified.
While Gian Piero Gasperini’s men are something of a novelty to Champions League viewers, as it is only their third season in the competition, former Napoli defender Albiol knows them very well indeed.
“When I was at Napoli, it was much easier to play against Inter, Juventus or Milan, because they were always pretty similar, whereas Atalanta were unpredictable and more difficult to prepare for,” said Albiol in his press conference.
“We know the Italian fans fill the stadium in a very intense fashion, they live for football. When we saw the teams we were up against in the draw, we knew who would cause us problems.
“However, we are ready and have already planned our approach. I hope that it will be enough to let us reach the Round of 16.”
Atalanta picked up a 1-1 draw in Spain for the opening Champions League group game.