In the Seattle backfield, Christine Michael gets the first shot at running back, with Thomas Rawls on the PUP list, but there is a clear rotation with Alex Collins and Zac Brooks seeing plenty of opportunities with the starters.
C.J. Prosise tweaked his hamstring at the beginning of practice and is not participating in team drills. It will probably take until the beginning of the preseason to figure out which of the backs is inching ahead of the rest.
Michael would seem to be the favorite to be first behind Rawls (assuming he's the starter) based on his second tour of duty with the team last year and playing pretty well. But there are some other names to keep an eye on as long as Rawls remains out.