Arsenal head into the north London derby this weekend with a serious selection headache. The Gunners’ midfield has been decimated over the past few weeks after Mikel Merino picked up an injury and Declan Rice was red-carded against Brighton. To make matters even worse, Martin Odegaard picked up an injury on international duty. After letting both Emile Smith Rowe and Fabio Vieira go this summer, replacing Odegaard this weekend isn’t a straightforward task. Speaking on the BBC Planet Premier League Podcast, Mark Chapman has been discussing how Arsenal deal with this crisis, and he says that he’s…