I think he’ll be a big miss. Arteta clearly likes to use him to add energy and bite when closing out games. I think it’s clear Xhaka and Ceballos is the first choice midfield at the moment but Torreira had an important role to play. Guenduzi and Willock are going to need to step up when called on.
It also seems that Bellerin has been playing with a groin tear that just is'nt healing. (apparently why he isnt crossing so much on his right foot) Might see Cdric replace him when he's fully fit.
