TAMPA – It was friendly fire. The decision by Bucs coach Dirk Koetter to terminate a guy he's been buddies with for nearly 40 years was not an easy one. But defensive line coach Jay Hayes was let go last Friday, an apparent fall guy for the 5-11 season.

Everybody figured there would be changes on the coaching staff. But the timing of this one, coming six weeks after the season, is not ideal.

Not for Hayes, who had been given a one-year club option like the rest of the Bucs' assistants only a few weeks ago. The best time to find a new job in the NFL has come and mostly gone.

For the same reason, the talent pool has been reduced for the Bucs.

A lot of good coaches already have been hired over the past few weeks by new staffs being formed by the Giants, Raiders, Cardinals, Bears, Lions and Colts, who hired Eagles offensive coordinator Frank Reich as head coach Sunday.

Rick Stroud discusses the Bucs’ decision to fire defensive line coach Jay Hayes six weeks after the end of the season. #Bucs #Buccaneers @TB_Times @NFLSTROUD https://t.co/It7eiRxiwV — TampaBayTimesSports (@TBTimes_Sports) February 12, 2018

And as it turns out, Koetter could be swapping one long-time coaching partner for another.

The Bucs plan to interview Ted Monachino, the Colts defensive coordinator for the past two seasons. Like Hayes, who has known Koetter since they were rival players at Idaho and Idaho State, Monachino has history with the Bucs head coach.

Monachino coached the defensive line under Koetter at Boise State and Arizona State. They were on Jack Del Rio's staff at Jacksonville with Bucs defensive coordinator Mike Smith.

Monachino's biggest achievement was winning a Super Bowl with the Baltimore Ravens, where he coached linebackers from 2010-15.

From the outside, it's uncertain why Koetter decided to make the move now. The Bucs were last in the NFL with 22 sacks, so it didn't take six weeks to discover that the lack of a pass rush, and the lack of production from the defensive line in general, was a big reason for the disappointing 2017 season.

And the Bucs pass rush was only slightly worse than the Colts, who had only 25 sacks last season.

So what happened?

The general belief at One Buc Place is that this was 100 percent Koetter's call. It wasn't a situation like after the 1999 season when the Glazer family insisted that Tony Dungy fire offensive coordinator Mike Shula, who was finally dismissed at the Pro Bowl.

Perhaps Koetter finally had some time after the Senior Bowl to do a deep dive or film study on the defensive line. Maybe interviews with players led to this decision. Maybe he just found out recently that Monachino would be available.

Certainly, Hayes didn't have the Steel Curtain to work with. Aside from six-time Pro Bowl defensive tackle Gerald McCoy, the biggest reason for optimism on the defensive line was Noah Spence, who had 5.5 sacks in an injury-plagued rookie season in 2016.

But Spence suffered another shoulder injury, this one ending his season after only three games, and the Bucs got almost no production from defensive ends Robert Ayers (two sacks) and William Gholston (zero sacks).

Nobody is going to hold a pity party for McCoy, but this will be the eighth defensive line coach he has worked with since coming to the Bucs as the No. 3 overall pick in 2010. That includes Bryan Cox, who was the front seven coach in 2012-13, working with Randy Melvin on the pass rush.

But this decision says something about Koetter and where the Bucs are entering 2018. The firing of Hayes tells you this has become a zero-sum game for the head coach, among others. Not that he was trying to signal more urgency, but if you're willing to do this to a friend and a pretty good coach, well, everyone is on the clock.

There may only be 32 of these NFL defensive line coaching jobs in the world, but frankly, you have to wonder how many people would be leery of moving their entire lives to Tampa when it could be for only one year.

So far, Koetter has made two major moves with his coaching staff. Todd Monken gave up his role as the receivers coach to be the full-time offensive coordinator, even though Koetter still plans to call plays. The Bucs stayed in house by replacing Monken with offensive assistant Skyler Fulton, who played for Koetter at ASU. Sensing a trend here?

There are a lot of coaches at One Buc who should probably keep their head down. Smith, offensive line coach George Warhop, running backs coach Tim Spencer, defensive backs coaches Jon Hoke and Brett Maxie were all spared despite underachieving units.

Then again, it's only February.

Contact Rick Stroud at stroudbucs@aol.com. Follow @NFLStroud