CB: Per Mertesacker
Was very comfortable mopping up against Burnley last week and put himself about to dominate the aerial duels. Against a physically robust Reading side who like to pump balls into the box, Mertesacker will have to be at his best.
CB: Laurent Koscielny
It will likely be up to Kosicelny to try and handle Pavel Pogrebnyak and the Frenchman will want to be doing a lot better than when he faced the Russian at the Madjeski Stadium in 2012, with the Gunners conceding a quite incredible four-goals before half time until eventually turning it around with the help of extra time to win 7-5.