The Facts: Injuries are starting to become a problem at running back for the Bills as Jackson joined Boobie Dixon on the sidelines Friday morning after hurting his hamstring. Jackson was hurt early in practice, and coach Rex Ryan said afterward that it could be as much as two weeks before Jackson returns.

Diehards Line:With Dixon already out for perhaps as long as a month with a calf muscle injury, the Bills are thin at the position.Thursday, the team signed 215-pound undrafted rookie Bronson Hill, so he'll take some of the reps, and Ryan said wide receiver/returner Marcus Thigpen may also get worked in. eSean McCoy has been back to full-time work the last two days, but he was battling soreness in his toe earlier in the week. The only fully-healthy backs are rookie Karlos Williams and Bryce Brown, and Brown didn't endear himself to Ryan Friday when fumbled, an issue that he has battled his whole career. ... Stay tuned. We'll follow up on Jackson as needed.