#3 Give the newbies a chance
Let's not forget, before the winter break, Arsenal had a very bright transfer window. They brought in Pablo Mari on loan from Flamengo and Cedric Soares on loan from Southampton. These two are positive defensive acquisitions that would certainly make an impact in the XI should they be given the chance.
Understandably, neither made their debut against Burnley since the transfers were fresh at the time. However, now that Arteta has been given time to assess the new signings, he may feel it would be best to give one or both of them a start against Newcastle United at the Emirates.
Mari is a brute defender who will stop at nothing to protect his goalkeeper and equally, Soares is a full-back who likes to put in a shift in the defensive third. These are areas of the game that Arteta may feel will benefit him against Newcastle. Especially with Soares, since Newcastle's full-backs like to press high.