As has often been the case for Mikel Arteta this season, the Arsenal manager finished the game against Liverpool with a much different back four than the one which started. Gabriel Magalhaes injured his left knee early in the second half and his Arsenal teammate Jurrien Timber also needed to come off shortly before the end. Timber appeared to be fatigued rather than injured, but it’s still a concern for the Gunners. That being said, Gabriel was replaced by Jakub Kiwior in the 54th minute, a back line that was then a far cry from Arteta’s strongest. Ben White and Thomas Partey were excellent on…