"It's important to know who they are," Ravens coach John Harbaugh said. "You have to check out what the jersey number is and the guy who's in that game. You have to know each guy, because they have versatility at running back. I think it's probably true for their whole offensive personnel. You have to know who's lined up where, what those guys do, how they're utilized, and then there's the unknown because it's a new season."