Arsene Wenger refuses to admit selecting David Ospina was a mistake after keeper's howler led to Arsenal defeat by Olympiacos

• e-mail

Arsene Wenger defended his decision to play David Ospina despite the goalkeeper's embarrassing howler in a calamitous night for Arsenal.

As Sportsmail revealed on Tuesday, the Colombian started ahead of regular No 1 Petr Cech against Olympiacos.

But Ospina carelessly carried the ball over his own goal line from a Kostas Fortounis corner to gift the visitors a 2-1 lead.

Arsene Wenger shows his frustration on the touchline during Arsenal's 3-2 defeat by Olympiacos

Wenger, sat next to assistant Steve Bould, watched his side slump to successive European losses

Wenger, though, refused to admit he made a mistake in selecting Ospina ahead of Cech.

'To say I regret the decision is always the simple thing. No keeper is mistake-free, it could have happened to Petr Cech as well. That's part of it,' said Wenger.

'Why did I make the decision? I don't give you why. I do not have to sit here and give you any explanation about every decision I make.

'You are capable to judge what I do and I leave you to that. I made the decisions and the selections for the team and I am responsible for them. And I know many things that you don't know. Or that you ignore.

'We cannot select the team by making a poll before the game and getting everybody's opinion.'

Wenger's misery was compounded by a hamstring injury to Laurent Koscielny, who is a major doubt for Sunday's clash against Manchester United.

David Ospina scored an own goal for Arsenal after flapping at a corner under no pressure

The Gunners keeper ended up bundling the ball over his own goal line to give Olympiacos a 2-1 lead

Benched Arsenal keeper Petr Cech (right) shakes hands with Olympicaos stopper Roberto after the game

Laurent Koscielny is now an injury concern for Arsenal after picking up a hamstring injury during the defeat