The last two NFL sack kings -- J.J. Watt (17.5 in 2015) and Justin Houston (22 in '14) -- are currently on the PUP list, recovering from offseason surgical procedures. While Watt is expected to return to the field before Houston, both prolific sack artists carry question marks as we head into the 2016 campaign.

Still, in a passing league, there are plenty of sacks to be had. And we've already heard some eye-opening forecasts around some of the league's elite pass rushers ...

At Cardinals camp, Patrick Peterson and Tyrann Mathieu are predicting that their new teammate, Chandler Jones, will rack up 20-plus sacks this season. That's nothing compared to Derek Carr's projection for Raiders teammate Khalil Mack: 30 sacks in 2016.

All of this begs the question: Who will lead the NFL in sacks this season?

Khalil Mack racked up 15 sacks and earned first-team All-Pro honors as both a defensive end and linebacker in 2015. Imagine what he'll do with another year of experience under his belt and Raiders head coach Jack Del Rio eager to unleash him on opposing quarterbacks once again.

Yes, Mack will feel the absence created by the suspension of Aldon Smith. But the Raiders also signed outside linebacker Bruce Irvin in free agency and he will be excited to have more pass-rushing opportunities than he found in Seattle.

In other words, Mack should be even scarier this coming fall. When healthy, J.J. Watt is always the pick. We are watching a Hall of Fame player in his prime. In addition, he has the flexibility to rush from any position along the line of scrimmage, as well as blitz from a linebacker position. This helps him take advantage of personnel mismatches.

But, since we don't know how Watt's health will be entering the season, I will pick Kahlil Mack. He has shown steady improvement as a player and pass rusher since his career started in Oakland. Mack will be helped by the addition of Bruce Irvin on the other side, especially on passing downs. The other thing that will help him: I expect the offense to continue its improvement behind Derek Carr. This will put the defense in a position to have more pass-rushing opportunities because the opposition will be playing from behind. With J.J. Watt's injury, we don't know what he's going to be able to do this year, so I'm taking the upset pick and going with Ziggy Ansah. He was so raw coming out of college and continues to get better every year. I don't think he has even scratched the surface of his potential. Ansah might not have 20 sacks this season, but 16 or 17 is within reach -- and could get him the crown. J.J. Watt could be limited early in the season, and that leaves the door open for a new sack leader. I watched the Raiders practice last week and let me tell you: Offenses are going to have a hard time against Bruce Irvin and Khalil Mack. Mack is poised to have a big season with Irvin, a complementary pass rusher, on the opposite site. Everson Griffen will lead the league in sacks this season because the Vikings are a team that, more often than not, should be playing from ahead. The emergence of Minnesota's offense with Adrian Peterson, Teddy Bridgewater and weapons in the passing game ( Stefon Diggs, Laquon Treadwell and Kyle Rudolph) will give the team early leads, allowing the defense to hunt.

In the past, the Vikings have been in a lot of close games, so the defense hasn't been able to attack. Now that the Vikings are going to be playing against teams that are chasing points, Griffen will have more opportunities to get after the passer. Khalil Mack is fully capable of improving off his 15-sack season in 2015, especially with Bruce Irvin now on the opposite side. Irvin will command attention, which will play in Mack's favor. If you leave Mack one-on-one, he will win 95 percent of the time. If the offense guesses wrong about where he's going to line up, he wins 100 percent of the time. He's going to take the crown this season.