article_snippet: Per Mertesacker could pay for some poor performances this season, with Dortmund centre half Neven Subotic and Aleksandar Dragovic of Dynamo
article_snippet: But the arrival of a new centre back in the summer is likely to have repercussions for Mertesacker.
article_snippet: And the arrival of a new centre-half could marginalise Mertesacker's role in Arsene Wenger's plans.
article_snippet: The capture of a new central defender could also have consequences for Calum Chambers.