I think Sherwood will probably take a look at everyone in the Summer and make his judgments. That is of course excluding the out of contracts and players on loan with purchase options that get activated. I'd expect the following players to all get a shot during pre-season.
LB: Cissokho, Bennett, Luna (possibly)
RB: Hutton, Lowton, Bacuna
CB: Clark, Okore, Baker, Senderos, Donacien, Kinsella.