The Washington Redskins have hired former Dallas Cowboys offensive coordinator/offensive line coach Bill Callahan, two people with knowledge of the situation confirmed, and have agreed to a three-year deal.

Bill Callahan, the former Raiders head coach and Dallas offensive coordinator, talks here with the Cowboys’ Jason Witten in June 2013. (Ron Jenkins/The Fort Worth Star-Telegram, via AP)

Callahan is a well-respected offensive line coach and also has experience as a head coach. He coached the Raiders to the Super Bowl in 2003, following the 2002 season, but they lost to the Tampa Bay Buccaneers. Bruce Allen, the Redskins’ team president, was general manager of the Raiders then.

Redskins offensive line coach Chris Foerster was interviewing with the Buffalo Bills and expected to take the same position there, reuniting him with Rex Ryan, with whom he coached in Baltimore.

Callahan will be charged with repairing an offensive line that struggled last season. The line features Pro Bowl left tackle Trent Williams, and a solid veteran in center Kory Lichtensteiger, but the other three positions need upgrading.

● Related: A look at how interior O-line played | Tackles

It remains to be seen if Callahan uses the same zone-blocking schemes that the Redskins have used since 2010, when Mike Shanahan came to town, and continued to run last season as they retained Foerster despite Gruden’s hiring, or if Callahan will overhaul the blocking schemes.

ESPN reported the agreement is “a very lucrative three-year deal.”

More from The Post:

Redskins still interested in Fangio, undecided on D-coordinator

New defensive coordinator will inherit a unit that needs a lot of work

Outsider: Reviewing the Redskins tackles

D.C. Sports Bog: Fassel recalls almost getting Redskins’ job

More NFL:  Home page | Sports Bog | Early Lead | Fancy Stats | Fantasy

Follow:  @MikeJonesWaPo | @lizclarketweet | @JReidPost | @Insider