Jonathan Stewart will share the backfield with Christian McCaffrey. He will be the power back who gets most of the carries on first and second down. McCaffrey will be the change-of-pace back used in passing situations and on third down.
There will be times when both are on the field, either in the backfield or with McCaffrey in the slot or at wide receiver.
Stewart was 11 yards shy of 1,000 yards in 2015 despite missing three games, and last year ran for over 800 yards and nine TDs. He received a one-year extension through 2018. McCaffrey will surely cut into Stewart's workload but it sounds like Stewart should continue to get early-down work as well as goal line carries.