The Miami Dolphins have said that Lamar Miller needs to develop a "more physical" playing style, according to a report.
The running back saw an increase in his workload during his second season in the NFL, finishing the 2013 season with 709 rushing yards and two touchdowns.
A team source told the Miami Herald: "[Miller and teammate Daniel Thomas are] a good complement to each other, and we like Miller's speed and explosiveness.
"Miller has the higher ceiling, but you wish he ran with a more physical [style]. And both have to improve as blockers."
Thomas saw fewer carries that Miller, managing 406 yards and four touchdowns.
