Assuming Fryatt is on the bench, he would almost certainly come off the bench before Prossy. Not sure I would have Fryatt on the bench this week though with him being ill.
I suspect that even if Hobbs is declared fit, SB will be struggling to decide whether to stick with the system that's got us to where we are so far; or with only three fit centre halfs, to not risk playing them all at this stage in the same game.
I dont see Hobbs starting today from whats been said on the radio. Fryatt looks to have his place on the bench though. 4-4-2 which allows Rosie to play and that keeps us strong at the back. Its a big week coming up and the extra few days rest will do Hobbs the world of good.