LONDON (AFP) - Arsenal star Mesut Oezil has apologised to the football club's supporters after squandering a penalty in Wednesday's 0-2 loss at home to Bayern Munich in the Champions League.

The German playmaker had an opportunity to put Arsenal ahead in the last 16 first-leg match with an early penalty, but his tame spot kick was saved by international team-mate Manuel Neuer.

After Arsenal goalkeeper Wojciech Szczesny had been sent off, Bayern went on to prevail through second-half goals from Toni Kroos and Thomas Mueller, leaving the reigning champions in a commanding position ahead of the second leg on March 11.

"The next morning doesn't feel better either," Oezil wrote on his official Facebook page. "Sorry guys - it wasn't planned that way. Outnumbered it was really hard to win against this team."

Oezil, a club-record 42.5 million pound (S$89.7 million) signing from Real Madrid last year, was roundly criticised in the British media following a lacklustre display in the game.

Arsenal shareholder Alisher Usmanov suggested that the 25-year-old's poor performance may have been down to fatigue.

Speaking to reporters as he left the Emirates Stadium on Wednesday, he said: "Oezil was not (playing) at his capacity, maybe because he is tired."

However, Oezil's team-mate and international colleague Per Mertesacker believes that the former Werder Bremen schemer is still finding his feet in north London.

"We have a lot of games here in England and everyone is tired, but it is not just up to Mesut," said the centre-back.

"It is up to everybody to encourage and come back. During the game we all need to encourage each other. Mesut has played a lot of games and he is a massive player.

"We need him at his best. Game by game, he will come back stronger."