Sometimes you don't cut the player until he passes his physical. It's the offseason no way to get that done.
I'd be very surprised, and disappointed, if we banked on having a rookie at Center this year even if that was for later in the season. First off that means we're gambling because we don't know who will be available. Or we reach way too early giving up value at another need position. With a new offense for everyone to learn I don't want a C who has to learn how to read the D and learn what the play is. I'd rather have a vet there even the lower level FAs like Shelton or Brown.
That doesn't mean don't draft a future center as I'd be on board with that. Just don't expect he'll be the answer this year. In the event of an injury I wouldn't even be surprised to see them move Jackson over and put a youngster at OG.