Both Tucker and Barner left Thursday's game with an injury, so Polk is not the only running back nursing an injury.
"That's unfortunate for Chris because I know how much he wants to be out there, but that's the game, coach Chip Kelly said of Polk's injury. "He's done everything he can from a rehab standpoint. It's not like he's not doing what he needs to do."
Logan gets his snaps
Bennie Logan was the only starter that played on Thursday. Logan missed the first preseason game, and Kelly said he needed playing time.
"I think Bennie will be the first to tell you he needed snaps," Kelly said. "Didn't play in the second half, but we wanted to get him some snaps in the first half. Of course at camp, he probably didn't have as many snaps as [Cedric Thornton] or [Fletcher Cox].
"So I wouldn't read anything into it. It was just a matter of making sure we had enough of Bennie and Bennie came out of it healthy. So we'll build upon it from there."
Logan played 12 snaps, the fewest of any defensive player.
Rookie Jaylen Watkins played 55 defensive snaps, which was the most on the team.
Offensive linemen Lane Johnson, Dennis Kelly, and Andrew Gardner played the entire game on offense.
Andrews, Kinne out?
Offensive lineman Josh Andrews will be released, Andrews' agent wrote on Twitter. Quarterback G.J. Kinne will be released, according to CSNPhilly.com.