The Oakland Raiders' search for an offensive coordinator -- their most important hire of the 2013 coaching season -- is over.

Oakland has hired Greg Olson as its offensive coordinator, according to an NFL source. The Raiders are expected to formally announce the hire in the coming days.

Olson was Jacksonville’s quarterbacks coach in 2012. Olson has had an extensive coaching career and will run an offense better adapted to Oakland’s talent base than that of Greg Knapp, who was fired after one season with the team. Knapp became Denver's quarterbacks coach Friday.

Olson is expected to run a downhill, power-run attack in Oakland. Primary tailback Darren McFadden excelled in such an offense in 2010-11; Knapp ran a zone-blocking run scheme that did not succeed with the Raiders.

Olson, who coached on Jon Gruden’s staff in Tampa Bay, has spent six full NFL seasons as an offensive coordinator, holding the position in Detroit, St. Louis and Tampa Bay. He worked with Rams running back Steven Jackson and Buccaneers quarterback Josh Freeman.

Olson has a solid reputation in the NFL. He has pieces to play with in Oakland, beginning with McFadden and quarterback Carson Palmer.

I think the right first step is going back to a power running scheme. Using the zone-blocking scheme was a mistake Oakland couldn’t overcome last season.

Olson might not be the sexiest of picks, but as long as he fits the personnel and works well with head coach Dennis Allen and the rest of the staff, Oakland should be improved on offense in 2013 as it tries to build from a disappointing 4-12 season in 2012.

Oakland still needs to hire a special-teams coach, an offensive-line coach and a linebackers coach. Bobby April is a candidate to be special-teams coach.