The San Francisco 49ers would seem to have a pretty clear No. 1 running back in Carlos Hyde, but there will be plenty of competition for reps behind him. And given the durability questions along with Chip Kelly's offensive philosophy, the second and third running backs could see plenty of work.

On Thursday, offensive coordinator Curtis Modkins had a chance to discuss some of the running back reserves. He was first asked about Kelvin Taylor. He was impressed with his work thus far, and said that it appeared that things were starting to slow down for the rookie. Of course, like many positions, it is hard to get a firm handle on the running backs without pads and full contact. But if he is picking up the playbook and understanding his assignments quicker and quicker, that's a big plus.

Modkins was asked about Shaun Draughn, he compared him to Theo Riddick, who played for Modkins in Detroit. Last season, Ameer Abdullah and Joique Bell got the bulk of the carries, but Riddick was a critical component in the passing game. Riddick caught 80 passes on 99 targets, for 697 yards and three touchdowns. His receptions, targets, and receiving yards were all third on the team, behind Calvin Johnson and Golden Tate.

Finally, Modkins was asked about DuJuan Harris. He described him as a guy who "brings a little juice," has some stop/start to him, and has impressive explosion.

The 49ers added both Draughn and Harris when injuries limited the running back depth chart. Draughn did solid work in place of Carlos Hyde and Reggie Bush. He was not an explosive option out of the backfield, but he kept the running game from completely floundering. After he was put on IR, the team signed Harris off the Baltimore Ravens practice squad. He looked a little bit more impressive, but they bring different skillsets that should make for an interesting competition along with Taylor and Mike Davis, behind Carlos Hyde.