UEFA will study reports from the referee and match delegates before deciding whether to take action against Villarreal after their fans threw objects at Arsenal captain Cesc Fabregas.

Fabregas, jeered throughout by the home support, was taking a corner, shortly after a clash with Sebastian Eguren, when what appeared to be paper boxes were hurled in his direction from the stands. Although the Spain midfielder was not hit, he picked up one of the objects and showed it to referee Tom Henning Ovrebo.

Arsenal manager Arsene Wenger said: "Certainly, UEFA will make an inquiry and make the right decisions."

Villarreal, meanwhile, are still confident of going through having drawn 1-1 at home to Panathinaikos in the last round before winning the second leg 2-1.

Forward Santi Cazorla, who was watching from the sidelines after breaking his leg on Saturday, said: "It's been a shame but we still have our chances.

"Although the scoreline favours them, we showed in Athens we are capable of scoring away from home. The first half was ours and we controlled the ball but in the second half Arsenal were better."

Villarreal president Fernando Roig said: "Although it's difficult, the tie is still open."