The last two NFL Defensive Players of the Year are also two of the league’s most underpaid — but that won’t last for long. Both Khalil Mack and Aaron Donald are holding out as they head into the final years of rookie contracts signed in 2014. If they don’t get paid with lucrative extensions this fall, they’ll still cash in with mega-deals next spring.

Both players have the potential to reset the market value for elite defensive talent. Mack has been the lone bright spot on an otherwise regrettable Oakland Raiders unit, commanding double- and triple- teams that lessened his stats in 2017 but not his impact. Donald has been the crown jewel of a dominant defensive line for the Los Angeles Rams. Each man will be looking to eclipse the six-year, $114 million deal with $70 million in guarantees Von Miller got more than two years ago — and they have Miller’s support, too.

The Rams and Raiders would be unwise to let either walk away, and it would be almost unheard of for a high-profile player like this to become an unrestricted free agent — each DPOY since 2010 has spent his entire career with a single team. But as both sit out the preseason in search of the contract they deserve, the chance it happens exists.

For the sake of argument, let’s assume each of these quarterback-crushing stalwarts hits free agency next year. It would be almost impossible to sign both to record-setting deals. So if you had the opportunity to choose, which standout defender would you pick to anchor your defense?

The case for: Rams DT Aaron Donald

This one is easy. Donald has a legitimate claim to be the best defensive tackle in the history of the NFL. Since entering the league in 2014, Aaron Donald is ninth in sacks with 39 — as a damn defensive tackle. That’s more than Cameron Jordan, Melvin Ingram, Carlos Dunlap, and Michael Bennett. His ability to completely dismantle entire offenses on a down-to-down basis is almost unparalleled.

aaron donald killed the falcons OL from the 1st play of the game. split zone action is the only reason this wasn't a sack pic.twitter.com/VrfovPw8PX — charles mcdonald (lakers 0-0) (@FourVerts) January 7, 2018

Donald sledgehammered his way through opposing offensive lines on his way to the 2017 Defensive Player of the Year award. According to Pro Football Focus, Donald finished with 91 total pressures and a 94.0 overall grade, both the top marks for all defensive players.

Don’t forget: he missed two games during the season.

Donald and Khalil Mack are both otherworldly, generational football talents. However, Donald’s ability to wreak havoc at a rate unlike anything we’ve measured before (outside of J.J. Watt’s run of terror from 2012-15), gives him the edge over Mack here. — Charles McDonald

The case for: Raiders DE/OLB Khalil Mack

Mack went from 2016 DPOY to mere Pro Bowler last year — but it wasn’t related to any kind of dropoff in talent or ability. Instead, Mack was let down by a deficient Oakland defensive line that failed to scare opposing offenses and left him staring and double and triple teams throughout the 2017 season.

And despite it all, he still notched double-digit sacks. For the third straight year.

Mack has been a revelation for the Raiders’ pass rush, but the team’s inability to bookend him on the other side of the line has lessened his impact on the edge. Players like Denico Autry, Jihad Ward, and Mario Edwards Jr. struggled to create pressure from the right side, leaving the All-Pro on an island on the left where opponents can either throw obstacles in his path or just straight-up run away from him.

Sometimes that’s not even enough, because Mack is basically a tiny grizzly bear. One hand is all it takes for him to drag you to the underworld.

Furthermore, Mack has been effective as a pass rusher from the line as an end and from the second level as a linebacker. While the addition of Bruce Irvin has pushed him to the trenches the past two seasons, he remains a flexible player who can fit in any scheme his coordinator throws at him. That versatility, much like Donald’s ability to play end or tackle, carries a ton of value for whichever team is lucky enough to have him.

Donald is awesome, but part of what has made him so special is a talented Rams lineup that effectively forces opponents to pick their poison — they can’t double-team Donald all the time when pass rushers like Michael Brockers, Robert Quinn before, and now Ndamukong Suh are there to take advantage of the weaknesses that creates. The Raiders don’t have that network in place for Mack, who can only count on Irvin to provide steady support in the pass rush.

Mack has done more with less over the course of his four-year career. Pay the man — and find him some reliable help on the right side so he can feast. — Christian D’Andrea

If you had to pick just one, would you pay Aaron Donald or Khalil Mack?