Arsenal boss Arsene Wenger admits he was unsurprised by comments from captain Per Mertesacker this week.

The German defender says his end of season retirement cannot come soon enough.

Wenger said: "How do I respond to that? I know that. It's not a surprise to me. To be a professional football player is about facing a huge level of expectation. First of all from yourself because these players are at the level that they are because they're very demanding with themselves.

"That creates stress of course, and the huge expectation level from the environment also creates the stress. To play at the level they play at today, you need to have a huge resistance to stress. Somewhere you're a little bit dependent on your body.

"To express what you want to do, you always need your body to be at your service and that creates stress because you never know how your body will respond, how well you will feel, how much your reflexes will be there in a game. It's always an uncertainty that creates the stress."