NASHVILLE, Tenn. -- Behind the scenes it was well known that Tennessee Titans offensive linemen were unimpressed with their position coach, Bob Bostad, over the last two years.

Right guard Chance Warmack put it on the record in a roundtable of offensive linemen with Pete Prisco of CBS Sports.

I had one dude (coach) who played D-III football at linebacker. And he's teaching me how to play offensive line? If there's nothing wrong with that, you tell me. I play offensive line. I don't play linebacker. I definitely didn't play D-III football. Not knocking D-III schools out there. We're talking about the highest level of football in the world. And you have a guy who has never put his hand in the dirt teaching me how to block. You don't think there's anything wrong with that? I appreciate a coach who is open-minded to questions and comments. They don't want to hear a question that questions their philosophy. When they are closed-minded, it stunts the growth of the offensive lineman.

Bostad played linebacker at Wisconsin-Stevens Point from 1986 to 1989.

Warmack's only other NFL position coach was Bruce Matthews, who played at USC and is in the Pro Football Hall of Fame. Mike Sullivan has been the Titans assistant offensive line coach since 2014. He played college ball at Miami and spent time with Dallas and Tampa Bay in the NFL. Arthur Smith was assistant offensive line and assistant tight ends coach in 2013. He played line at North Carolina. Smith is now the team's tight end coach.

Bostad was Ken Whisenhunt’s hire to coach the Titans' offensive line in 2014. The best piece of his resume was his work in the same post at Wisconsin developing some quality linemen.

Mike Mularkey let Bostad walk when he got the full-time head-coaching job, and hired Pro Football Hall of Fame lineman Russ Grimm to coach the line.

I don’t buy that a coach has to have played the position he coaches at a high level in order to be effective at his job. But Bostad was not very effective at his job, as Warmack was not especially effective at his, either.

Bostad is now coaching tight ends and fullbacks at Northern Illinois.

The Titans declined to exercise a fifth-year option on Warmack for 2017. The 10th pick in the 2013 draft enters his fourth season as the incumbent starting right guard.

But Mularkey recently left open the possibility that the Titans consider Warmack on the left side, where he played at Alabama.