Where's Alzate?
Since Potter used him in every possible and impossible position with good results we know he likes Alzate and believes he is good enough.
Him being on the bench or left out of the squad tells me something is wrong (unless he has injury struggles), maybe personal stuff or he just fell into the trap and started slacking in training once he thought he was "established". Happens a lot.
Either way I'm sure he'll be back when ready.