The 49ers backfield had a lot of mouths to feed last year, but Mostert announced early he wasn't going to be lost in the shuffle. A 151-yard eruption in Week 2 made him a waiver-wire darling, and while he had ups and downs afterward, by season's end he had moved to the top of the depth chart in Kyle Shanahan's RB-friendly offense. Mostert found the end zone at least once in every game Weeks 12 to 17, piling up 515 scrimmage yards and eight total scores in those six games, before sending the Packers home in the NFC championship game with 220 rushing yards and four touchdowns. Not bad for a guy who was typecast as a special teams player and bounced through five organizations in his first three NFL seasons after going undrafted out of Purdue. Mostert's best asset is his electric speed in the open field - he runs a 4.34 40 - and no back in the league turned a larger percentage of his carries into gains of at least 15 yards. He even flashed a bit of power when necessary, ranking 18th among 46 qualified running backs in broken tackle rate and 23rd in average yards after contact (2.2). Mostert said he bulked up this offseason in anticipation of a larger workload this year, though Tevin Coleman and Jerick McKinnon remain on the roster, while Matt Breida was traded to Miami in April. Shanahan's long-standing preference for multi-player backfields makes a bell-cow role for Mostert unlikely, but even a modest increase in volume to 200 carries could allow for a big impact in an efficient offense.