Cleveland Browns offensive coordinator Kyle Shanahan is considering leaving the team because of friction among the coaching staff and front office, Cleveland.com reported Wednesday.

Shanahan, among others, is a candidate to fill the head-coaching vacancy with the Buffalo Bills. He reportedly will interview for the job Thursday morning.

ESPN.com reported that Shanahan hasn’t notified the Browns about his unhappiness in Cleveland. ESPN’s source questioned the Cleveland.com report.

According to Cleveland.com, Shanahan also is intrigued by the idea of coaching again under his father, Mike Shanahan, with whom he worked for four years on the Washington Redskins staff as offensive coordinator before both were fired after last season.

The Bills, San Francisco 49ers and Oakland Raiders already have interviewed Mike Shanahan and would consider hiring the father-son duo with Mike as head coach and Kyle as offensive coordinator, according to Cleveland.com. Mike Shanahan has another interview slated with the Chicago Bears, according to reports.

Cleveland.com reported one source as saying some coaches became angered when play calls were recently requested or suggested via text from the press box by a high-ranking non-coaching staff member.

ESPN.com said the Browns’ situation at quarterback also provided significant friction as the front office placed pressure to have rookie Johnny Manziel play over starter Brian Hoyer.

Manziel started two games this season and completed 18 of 35 passes for 175 yards and added nine rushes for 29 yards. He was placed on injured reserve after injuring his hamstring in Week 16 against the Carolina Panthers.