Guard Chris Chester, left, and center Will Montgomery, right, run sprints at training camp July 30. (John McDonnell/THE WASHINGTON POST)

It’s not clear whether Chester will play in Thursday night’s preseason opener at Buffalo. The Redskins already are without two injured starters on their offensive line, right tackle Jammal Brown and left guard Kory Lichtensteiger.

Adam Gettis filled in at right guard with the starting offense for the remainder of the practice.

Shanahan reiterated Monday that he expects quarterback Robert Griffin III and the team’s other starters to play 12 to 20 snaps against the Bills.

Shanahan said his advice to Griffin will be to allow plays to develop and not force things.

Veteran quarterback Rex Grossman will play with the second team and rookie Kirk Cousins will play with the third-string offense, according to Shanahan.

Shanahan said he stopped Monday’s practice briefly because he saw a shot taken that he felt could have produced an injury. He stressed to his players, he said, that there’s a fine line between being competitive on the field and being smart.