Mikel Arteta has admitted he’s been ‘very impressed’ by one player who left Arsenal last summer. The Gunners boss has been speaking to the media ahead of tonight’s second leg against Bayern Munich in the Champions League. Arsenal will be hoping to get back to winning ways after a disappointing home defeat to Aston Villa on Sunday. While Bayern haven’t been at their best this season, they caused Arsenal real problems on the counter at the Emirates Stadium last week. The first leg ended in a 2-2 draw thanks to a late equaliser from Leandro Trossard and Bayern will fancy their chances at the Alli…