Ronnie Brown, San Diego Chargers (No. 29-Ranked RB)
Ryan Mathews hasn't yet been cleared for contact, according to Scott Bair of the North County TImes, and he's not going to play in the team's regular season opener against the Oakland Raiders.
That makes Brown the Chargers' No. 1 option at the running back position. Norv Turner, though he's known as a passing guru, doesn't abandon the running game. Brown will get plenty of opportunities to pound the rock, and though the Raiders are stout up front, he'll be productive.
Robert Turbin, Seattle Seahawks (No. 38-Ranked RB)
Marshawn Lynch is questionable for the Seahawks' first regular season contest against the Arizona Cardinals, according to the AP. He's suffering from back spasms, and even if he does play, I expect Turbin to see plenty of action.
The Cardinals have a really good defense, but the Seahawks were able to run the ball effectively against good defenses last year.
I don't expect Turbin to go off for 100-plus yards and two touchdowns, but he'll have a productive day and is a good option as a RB2 or flex.
Alfred Morris, Washington Redskins (No. 44-Ranked RB)
Mike Shanahan held Morris out of the team's last preseason game, treating him like a starter. That bodes well for Morris and anyone who has him on their fantasy team.
Morris is a quintessential Shanahan running back. He was drafted in the sixth round out of Florida Atlantic this past spring, and he has taken advantage of injuries to other backs to make his way to the top of the depth chart.
Shanahan will be sure to pound the ball between the tackles in order to protect his rookie quarterback, and out of the three sleepers I've listed here, I expect Morris to have the biggest game.