I've been thinking about this for the past few weeks. Carrasco and Joseph do a decent job at CM but are more defensive midfielders in the long run. That leaves Alonso and either one of them basically sitting at CDM. Playing two deep defensive mid-fielders is good for stifling attacks but pretty poor for creating offense. I think it may be time to play Mario (if we end up keeping him) at CM with Ozzie to really utilize that creative counter attack spark and get our forwards the ball in dangerous places. Here's how the formation would end up looking
Neagle - Martins
Johnson - Rosales
Burch - Traore - Ianni - Yedlin
Martinez loves to drift around the field so he will never truly be playing one position. He'll move back to CDM, up to CAM and most likely switch with Rosales every once in a while. His passing and crossing is hands down better than Servando and is much more creative and risky than Joseph. I think is he a great temporary option for CM and is possibly the only one who could actually unleash the speed of Neagle and Martins on a fairly consistent basis.