49ers hire Curtis Modkins as offensive coordinator; fire defensive boss Eric Mangini

SANTA CLARA - Chip Kelly said he's looking for an assortment of ideas and backgrounds on offense, and he's getting just that in his new offensive coordinator, Curtis Modkins.

On Friday Kelly and the 49ers decided on Modkins, 45, to help him run his offense. Modkins has been the running backs coach in Buffalo and most recently Detroit.

In both places he favored a running backs-by-committee approach - Marshawn Lynch was one of his rushers with the Bills - and was well versed in power running. Kelly, who will call the plays for San Francisco, favored zone-blocking schemes with the Eagles.

“I'm really looking for diversity, someone that comes from another system so that we can continue to add and make what we do better,” Kelly said Wednesday. “I really want to bring some people in that have some different viewpoints, have some different ideas and have done it differently.

“Then we, collectively, as a group, come together and (do) what's the best based on the personnel we have for us to be successful offensively.”

Modkins joined the Lions in 2013 and was given the title of run-game coordinator. He was retained the following year when Jim Caldwell took over for Jim Schwartz as head coach but his role was reduced to running backs coach.

Still, when Detroit's running attack began sluggishly last season, Modkins was promoted to manage that area, and the Lions had better results.

Detroit had no 100-yard rushing games in the first half of the season but had five in a row after Modkins handled more duties and Jim Bob Cooter took over as offensive coordinator.

Rookie running back Ameer Abdullah averaged 3.6 yards per carry in the first half of the season and 4.7 yards in the second half when Modkins coordinated the rushing attack.

The 49ers, meanwhile, ranked 31st in offense last season and struggled for consistency after their top rusher, Carlos Hyde, broke his foot in Week 5.

The team turned to a number of runners from that point forth, including rookie Mike Davis, Shaun Draughn and DuJuan Harris. All of them likely will get a chance to vie for roles during the coming offseason.

The 49ers have not yet announced any hires to Kelly's staff beyond running backs coach Tom Rathman.

MANGINI FIRED

Add Eric Mangini to the growing list of 49ers assistants that Chip Kelly has declined to keep.

According to Fox Sports, the 49ers fired Mangini on Friday. Additionally, the team has parted ways with last year's offensive coordinator, Geep Chryst, and with special teams coordinator Thomas McGaughey Jr.

Mangini's defense, which was wracked by retirements before the season and by injuries during the season, finished 29th in yards allowed, 31st in takeaways and 29th in sacks.

The 49ers' first choice to replace him, Texans linebackers coach Mike Vrabel, decided to remain with Houston instead. Kelly interviewed Mangini last week and he originally was not one of the coaches whose contracts were terminated.

The other known candidates for defensive coordinator are last season's outside linebackers coach, Jason Tarver, and Ravens linebackers coach Don Martindale.

Both have experience running an NFL defense. Tarver, 41, coordinated the Raiders defense from 2012 to 2014 and Martindale, 52, did so with the Broncos in 2010.