A visibly frustrated Arsene Wenger said it has been a ‘horrible week’ for Arsenal after a 2-1 defeat at Manchester City capped two damaging losses in the North West.

The Gunners threw away a position of strength again today after they went into the break 1-0 up through a fifth minute Theo Walcott goal against Pep Guardiola’s side – only to concede goals from Leroy Sane and Raheem Sterling.

It was the second disappointing defeat in a week following the 2-1 loss to Everton at Goodison Park on Tuesday – again after they took the lead.

Wenger said: “It has been a horrible week.

“If you want to be challenging for the top you have to keep clean sheets – and for a while we have not kept any clean sheets.

“We were a bit short in the second half and they were very aggressive.

“It is disappointing because we have given two good performances this week – and lost two games to offside goals.

“We just have to keep going and to win our next match.”

Wenger also confirmed Alex Oxlade-Chamberlain has a ‘muscular’ injury, possibly a hamstring strain, but he will know more tomorrow as the Gunners face a busy festive programme of matches after Christmas.

Pep Guardiola admitted his team had spent 2.5 extra hours on the training ground this week in order to become more effective at winning second balls – which was evident in his team’s victory, adding “The time we spent working on how to win our second balls against Arsenal worked today.”