Former Arsenal midfielder Charlie Nicholas has stated that Arsene Wenger must shoulder some of the blame for the Champions League defeat to Olympiacos on Tuesday for picking David Ospina over Petr Cech.

The Gunners boss rested Cech for the visit of the Greek outfit to the Emirates Stadium, but his replacement Ospina dropped a corner over his line as the visitors went on to secure a 3-2 victory.

Wenger made five changes to the side that won 5-2 at Leicester City on Saturday, and Nicholas has said that he does not understand why the Frenchman felt the need to alter the lineup.

"They had some momentum after the weekend but the way that they lost was criminal. Wenger has to take full responsibility for playing Ospina ahead of Cech," Nicholas told Sky Sports News.

"The first goal is a deflection but the second one is a basic corner. He's not under any pressure and all he's got to do is catch and hold it.

"Even though [Alexis] Sanchez gets them back into it, the third goal is shambolic. Gabriel is slack and slow and [Per] Mertesacker is not quick enough to cover."

Arsenal are bottom of Group F after losing their first two games.