Perhaps Sanchez was never the sub keeper because the skills needed of a sub goalkeeper are viewed different to those of a second choice keeper? Especially if you want your second choice keeper to be playing regularly, thus is off making appearances with the under 23s the day before/after the current premier league. While your back up keeper is there on the bench prepared with the right attitude to step in on the unlikely event that he is needed.
Then With Sanchez stepping into first choice, perhaps Ryan not being on the bench is an indication of how badly he has taken being dropped, or perhaps an indication that his being dropped isn't about performance but something else, or perhaps it is about rewarding the back up goalkeeper for his professionalism in seeing the younger guy jump ahead him, or perhaps it's about not wanting Maty on the bench so everyone can look to him if Sanchez messes up as if to say 'wouldn't happen with him on the pitch' putting added pressure on the youngster.
