The Pittsburgh Steelers have opted not to re-sign out-of-contract offensive coordinator Todd Haley, according to NFL Network’s Ian Rapoport.

Haley had been Pittsburgh’s offensive coordinator since 2012. He took over from Bruce Arians, whom the Steelers also moved on from after similarly allowing his contract to expire.

Haley had what should be considered a successful time in Pittsburgh. With talented offensive players led by the Killer B’s (Ben Roethlisberger, Antonio Brown, and Le’Veon Bell) at his disposal, Haley’s offenses were consistently one of the most potent in the entire league during his six-year stint.

The Steelers finished eighth in the league in points per game this season (25.4) but were third in both total yards (377.9) and passing yards (273.8).

Despite Haley’s on-field success, though, he reportedly didn’t have the greatest relationships with his staff or key players, particularly Roethlisberger. The two hardly interacted on the sidelines and had a generally rocky relationship with one another. It even came to a point where Roethlisberger publicly brought up his thoughts about retirement last year due to frustration with Haley.

Head coach Mike Tomlin, who is also facing criticism and calls for his job following their shocking playoff loss to the Jacksonville Jaguars, must now find Haley’s replacement. Quarterbacks coach Bill Fichtner is reportedly the favorite to get the job.

Fichtner, 54, has no play-calling experience in the NFL level but was an offensive coordinator for 10 years in college for Arkansas State and Memphis. He’s been the QB coach in Pittsburgh since 2010 and reportedly has a good rapport with Roethlisberger.