Could it be messy? Yes. Could it be a difficult relationship to manage? Yes. Would it attract a tremendous amount of unwanted media attention? Oh 100 percent yes.

But, even after taking all that into account, should the San Francisco 49ers call Bill Belichick about their now vacant defensive coordinator position? Absolutely.

The Niners are looking for a new coordinator after they made the decision to part with Steve Wilks after just one season in the post.

Wilks' woes

Wilks was fired despite the defense playing well for long periods in the 49ers' overtime loss to the Kansas City Chiefs in Super Bowl 58. 

San Francisco did not give up a touchdown until Patrick Mahomes' 16-yard strike to Marquez Valdes-Scantling, which came after a muffed punt, in the third quarter. After that, however, the Niners allowed drives of 69, 64 and 75 yards resulting in 12 Kansas City points, including the game-winning touchdown.

That collapse followed a postseason in which the 49ers had continually struggled to stop the run, a problem that initially reared its head down the stretch run of the regular season.

Defensive end Nick Bosa, per NBC Sports Bay Area, appeared to point to a lack of defensive preparation as reason for the Niners' struggles stopping Patrick Mahomes as a runner in the second half and overtime.

With such comments coming at the end of a season in which Wilks moved from the coaching booth to the sideline to improve communication with his players following a three-game losing streak, during which there was talk about the front being disconnected from coverage, it shouldn't be too much of a surprise that San Francisco elected to make a change.

Defense still a Belichick strength

All the problems that arose during Wilks' tenure would be unlikely to be repeated with Belichick in post. For all the New England Patriots' struggles in his final year as head coach, defense was not one of them.

New England's defense ranked eighth in Expected Points Added per play, above the 49ers in 12th by that measure, and was ninth in DVOA. More pertinently, against the run the Patriots ranked second in EPA per play. The 49ers were 26th.

Of course, the Patriots ran a three-man front under Belichick while the 49ers during Shanahan's head-coaching tenure have worked with four down defensive linemen.

However, with Shanahan indicating he is open to hiring a coach who hasn't previously run the 49ers' system, there is little reason for that to prevent them exploring the possibility of hiring Belichick, whose ability to prepare his defensive players, communicate with them and put them in a position to succeed has been unmatched over the course of his career as a defensive play-caller.

A strong relationship

It would, unquestionably, be awkward having the greatest head coach of all time on the sideline alongside Shanahan, and there's obviously reason for substantial doubt that Belichick would even be interested in being a coordinator again after interviewing twice for the Atlanta Falcons' head coach position after his departure from the Patriots.

But the Shanahans are well documented as having a great relationship with Belichick. Though the response is unlikely to be a positive one, it's worth seeing if that strong relationship could be used to help convince Belichick to spend a year as a defensive coordinator and refresh his image with a strong season overseeing one of the most talented defenses in football.

There would have to be some compromise on scheme and there would be the obvious question of whether Belichick would be willing to do weekly press conferences, a practice for which he clearly has little time. Even after agreeing all that, there's still the overriding issue of whether he'd be willing to take a step down. After winning six Super Bowls as a head coach, there's every reason for Belichick to believe he's above being a coordinator at this point in his career.

But that doesn't mean the 49ers shouldn't call. Belichick could quickly shut down the idea, he could be open to it, or he could indicate he'd be more interested in some kind of defensive consultancy role, a capacity in which he could clearly be of use to the 49ers.

The point is, you don't know until you ask. Shanahan insisted on Wednesday he will go into the process of finding a new defensive coordinator with an open mind. That open-minded approach should include being willing to swing for the fences and enquiring to see if the finest defensive mind available on the market might be open to reprising a role he hasn't held since 1999.

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