After another defensive collapse Sunday to the Oakland Raiders, the Lions need to resolve their defensive woes and fast.

Not to single out just one poor performer because collectively, the defense has struggled.

However, no one player has arguably been worse than Lions starting middle linebacker Jarrad Davis.

As you may have heard already, Davis, the Lions' 2017 first-round pick, has the worst Pro Football Focus grade of all qualifying linebackers in the NFL.

Even more worrisome, Davis is ranked dead last for all defenders that have played at least 100 defensive snaps.

Davis has underwhelmed against the run, against the pass and in securing tackles -- basically all aspects of the game.

If there is one thing that Davis does do well, though, it's rushing the quarterback.

Currently, he has PFF's third-highest pass-rushing productivity rate for all off-ball linebackers.

The third-year pro has pressured opposing quarterbacks 12 times on his 41 rush attempts.

It begs the question: Why is Davis only getting after the QB on 18 percent of passing plays?

For comparison's sake, fellow linebacker Christian Jones goes after the passer on 33 percent of the passing plays he's in on.

Meanwhile, rookie linebacker Jahlani Tavai does so at a 27 percent clip.

Yes, Davis is the most athletic linebacker on the team.

Despite his coverage flaws, it's a tough task for anyone in the starting linebacker unit to cover today's uber agile backs and tight ends.

Surprisingly enough, however, Tavai has done a decent job in his limited coverage opportunities.

Tavai has the best "coverage snaps per reception" rate and the fourth-best "yards allowed per coverage snap" rate for linebackers in the NFL (among LBs that have taken a minimum of 20 percent of their team's snaps).

It is important to note, though, that Tavai's responsibilities in the pass game are quite different than what is expected of Davis.

As previously mentioned, Tavai rushes the quarterback more frequently than Davis, but is often responsible for covering smaller or shorter areas.

Given the way Davis has performed so far in his career, what could it hurt to expand Tavai's role in the middle and to free up Davis to do what he does best -- rush the passer.

Unfortunately, it may not be that easy.

Davis is not a small linebacker in the eyes of the NFL.

Standing at 6-foot-1 and weighing in at 245 pounds, Davis would have been the third-heaviest off-ball linebacker at this year's combine.

The only two linebackers that weighed more: Tavai and Tre Lamar, both of whom were nabbed by the Lions.

If Davis was to be moved to the edge, could his skills be best utilized at the JACK position, a la Devon Kennard?

Kennard is 6-foot-3, 256 pounds, mind you.

The Lions also drafted Austin Bryant, who stands at 6-foot-6, 261 pounds, in the fourth round to play behind Kennard.

In Matt Patricia's scheme, he wants big, lengthy players. Guys that can hold up at the point of attack and set the edge in the run game, but can also get after the quarterback or drop into the flats -- in so many words, be a "JACK" of all trades.

Davis is big, but he definitely doesn't fit the JACK linebacker mold in Patricia's defense.

He also struggles to not get moved around by bigger linemen in the run game.

That can't happen in this scheme on the edge. The outside gap control is far too important.

We also have not seen Davis take on pass-blocking NFL tackles.

Two reasons he is so effective at getting to the quarterback are the element of surprise and stunts that match him up against running backs.

Who's to say that he would continue to have similar success against players that are paid big money to block.

Now, I'm not suggesting that Davis shouldn't rush the passer more. In my mind, he should.

Through more stunts and creative blitzes, Davis looks like a heat-sealing missile coming up the middle.

Maybe, though, Davis could overcome his relatively diminutive stature while playing on the line.

It probably wouldn't be too much worse than what he is doing in the middle of the field.

The Lions, at the very least, could test the waters with Davis on the outside, in a few obvious pass situations.

One thing is for sure, however.

Something needs to change on defense, and dramatic shake-ups should not be ruled out.

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