I imagine each team will go a different way, but I suspect that as the season wears on, teams are going to give starters fewer game snaps where possible, and instead rotate a bit more often.
For the Rams that didn't play starters in the preseason, I imagine they'll go a couple more games before the rotations get more robust. And of course it will depend on how the game is going. But if possible, I can imagine the Rams giving Whitworth fewer snaps where possible (with protecting Stafford the key here, the decision). The same with AD and a few other guys as well.