PITTSBURGH -- Mike Tomlin has another coaching spot to fill, and this time he has to replace one of his most trusted lieutenants.
Running backs Kirby Wilson is leaving Pittsburgh for the same position with the Minnesota Vikings, a source confirmed to ESPN.
The Pittsburgh Post-Gazette first reported Wilson's departure, which is not yet official, hours after reporting that Wilson was no longer a candidate to become the Ravens’ offensive coordinator.
Wilson twice interviewed for the opening in Baltimore -- he was one of three finalists for the job -- and his departure leaves just five assistants on the staff who have been with Tomlin since he became the Steelers’ head coach in 2007.
The Steelers permitted Wilson to pursue other jobs even though he had one year left on his contract and was significantly involved in crafting game plans.
The one question that will trail Wilson out of Pittsburgh is what might have been for the well-traveled assistant.
Wilson would have been one of the top candidates to take over at offensive coordinator in 2012 after the Steelers did not renew Bruce Arians’ contract. But Wilson was badly burned in house fire about a month earlier, and he couldn’t start working again -- even on a limited basis -- for more three months after the blaze that nearly cost him his life.
The Steelers hired Todd Haley to replace Arians, and when it became apparent that Haley would return in 2014 Wilson started looking around for other opportunities with Tomlin’s blessing.
The loss of Wilson comes three days after the Steelers hired Mike Munchak as their next offensive line coach. Running backs coach is the only position Tomlin is expected to have to fill with both coordinators returning as well as linebackers coach Keith Butler.
Butler had been a candidate to join Ken Whisenhunt’s staff in Tennessee as the defensive coordinator but he never interviewed for the position.
Bell, under Wilson’s tutelage, rushed for 860 yards in 2013 despite missing the first three games of the season. The second-round draft pick also broke Franco Harris’ Steelers’ record for yards from scrimmage by a rookie with 1,259 yards and established himself as a focal point of the offense in the coming seasons.
Wilson will join first-year coach Mike Zimmer in Minnesota, and he will work with the best running back in the NFL in Adrian Peterson.
Peterson rushed for 1,266 yards and 10 touchdowns in 2013 despite weathering foot and groin injuries, the latter of which sidelined him for two of the Vikings’ last three games.
Peterson had groin surgery last week but the Vikings said he should be fully healthy after a six-week recovery period.