Who is the 49ers' Unsung Hero on Defense?

They call him "The Shark."

Recognizing the San Francisco 49ers' defense as elite doesn't take much football sense to figure out. Even a blind man can see how stout they were on that side of the ball.

With players like Nick Bosa, Richard Sherman and Arik Armstead, it is clear as to why they were so dangerous last season. However, it wasn't just these big-name players that made this defense so elite. 

There are plenty of players who do not get the recognition they deserve. These players are unsung heroes since they play at a high level without being acknowledged. But there is one specific player who does not get enough credit for his performance.

So who is the 49ers' unsung hero on defense?

Slot cornerback K'Waun Williams is far and away the most overlooked player on the defense. His impact is felt in both run and pass defense, which is an uncommon thing to see from a corner. In fact, just calling him a slot cornerback does not do him justice. He is simply an all-around defender, considering how strong he plays in both facets of the game.

First and foremost, slot corner is arguably the second-most difficult position there is. Playing that position against the pass means every route combination is on the table. If a corner is on the outside, they can throw away some route possibilities. But playing in the slot makes every route type available. 

Williams has to be ready at all times. On top of that, he has to defend against the run because he is so close to the ball at the line of scrimmage. What is crazy about him is that when it is a run, he has no issues about sticking his head in there first. "The Shark" is what his teammates call him and, considering how aggressive he plays, you get why he got the name.

Once again, you hardly see cornerbacks play like this. Williams is essentially a slot corner/linebacker with how he plays out there. Because of him, the 49ers can roll out nickel formations easily since he plays the run so well. He acts as a third linebacker in the base defense practically. 

In this sense, Williams is the 49ers' fourth-best linebacker. He is also the team's second-best player in the secondary after Richard Sherman. You heard that right. Williams is worth more to the defense than even Jimmie Ward, which isn't a slight. It is just that Williams does so much more and is in more of an impact role. 

2020 is the final-year of Williams' deal. After that, he will be an unrestricted free agent, which will put the 49ers in a pickle. He is such a skilled player, and the odds are he will still be playing at a high level next season. The 49ers just might end up being priced out for his services. But the good news at least is that they have him for one more season. And if the 49ers are wise enough, they will strongly consider retaining "The Shark's" services.