Modkins will take over the job that Geep Chryst held last year. The 49ers fired him after finishing 31st in the NFL in total offense and last in scoring during his first season as the offensive coordinator.
The 45-year-old Modkins comes to San Francisco after spending three seasons with the Lions. Even though Detroit's running game finished among the bottom five in rushing yards in each of the past two years, Modkins earned high marks for helping clean things up.
According to Justin Rogers of MLive.com, after the team promoted Modkins to assist offensive coordinator Jim Bob Cooter in the middle of the 2015 season, the running game took off:
Even though the team had to abandon the run early in a blowout loss to the Kansas City Chiefs, Detroit averaged a season high 5.8 yards on 14 carries in the contest.
And after failing to top 100 yards rushing, as a team, the first nine games of the season, Detroit accomplished the feat five weeks in a row, starting against the Oakland Raiders in Week 10.
Modkins has experience as an offensive coordinator, serving in that role with the Buffalo Bills from 2010 to 2012.
However, Kelly said during his introductory press conference that he will be calling the offensive plays. Matt Barrows of the Sacramento Bee also noted that Modkins' power-blocking scheme differs from Kelly's preferred zone-blocking scheme in Philadelphia.
There will be plenty of time for Modkins and Kelly to sort out how their offense will work, especially since they may not even have their quarterback on the roster, depending on what happens with Colin Kaepernick and Blaine Gabbert.
The big-picture item is helping San Francisco's offense return to competency after it bottomed out last season. Modkins has a recent history of success, so this is a positive step forward in the 49ers' rebuilding effort.