Bob Quinn's overhaul continued Monday with the announcement of a new running backs coach. David Walker has been hired to fill the void left by Curtis Modkins.

Modkins, who had been hired in San Francisco to be Chip Kelly's offensive coordinator, was the team's running backs coach since 2013. The Lions ranked 17th, 28th and 32nd in team rushing yards in Modkins three years in charge of the running game.

Walker worked under Caldwell in Indianapolis and served as the Colts' running backs coach from 2011-2014. During that time the Colts never reached higher than 20th in the league in team rushing.

Walker comes in to a running back platoon that features Joique Bell, Ameer Abdullah, Theo Riddick and Zach Zenner. During his time with Indianapolis, Walker had running backs like Trent Richardson, Boom Herron, Joseph Addai and Dpnald Brown.

At least for Walker, there's nowhere to go but up in terms of last year's team output.