Alfred Finnbogason
Alfred Finnbogason scored the winner for Olympiacos as Arsenal suffered their second defeat in the group stages of the Champions LeagueGetty

Arsenal have been criticised as the team who "don't want to defend" by Olympiacos' Alfred Finnbogason, who scored the winner in his side's 3-2 victory in the Champions League clash. The striker scored the winner as the Gunners suffered a second straight defeat in the European competition.

The 26-year-old Iceland international is on loan with the Greek club from Real Sociedad. Arsene Wenger saw his side concede twice from set pieces, but those goals were cancelled by Theo Walcott's first half striker and Alexis Sanchez's 66th minute header.

Less than 60 seconds after the former Barcelona forward equalised for the north London club, Finnbogason scored the third goal for Olympiacos. The on-loan striker revealed how his side took advantage of Arsenal's weakness while defending corners.

"The first corner is something we practise on the training pitch because we know they have no man on the edge of the box," Finnbogason said, as quoted by the Guardian. "When you play against this team you know they're going to have a lot of the ball. You have to defend well, have the lines tight and use your time when you have spaces. And you know you're going to have spaces because they don't want to defend. So our plan worked."

The Emirates club host Manchester United in the next Premier League clash on 4 October. The Gunners centre-back Per Mertesacker has urged his teammates to bounce back when they face the 20-time English champions.

The German international's comments were echoed by his centre-back partner Gabriel Paulista. The former Villarreal man claims Wenger's side have an obligation to win against United, who sealed a 2-1 Champions League victory over Wolfsburg.

"Every game is very important and Sunday is the same. We are at home and we have an obligation to win at home. Things are not turning out well in the Champions League. In the Premier League we are fine but in the Champions League – I don't know what to say," Paulista explained.