JACKSONVILLE, Fla. -- A very athletic defensive lineman with a good mix of quickness and strength.

A big wide receiver with 4.34 speed and the ability to go up and get the ball.

A rangy, hard-hitting safety versatile enough to play both spots.

And a mammoth offensive tackle who didn't allow a sack in his final season.

It would not have been a big surprise if any one of those draft picks cracked the Jacksonville Jaguars' starting lineup in 2018. Instead, the first of the team's seven draft picks to do so is one of the Jaguars' two seventh-rounders.

Leon Jacobs, who played in more games than any other player in FBS history (59) while at Wisconsin, has been the starter at strongside linebacker since the day training camp opened. Cracking the lineup of what is arguably the NFL's best defense is a huge step for a guy whose only goal after the Jaguars selected him 230th overall was to find a way to make the 53-man roster.

"That was my No. 1 [goal] -- be a special-teams guy," Jacobs said. "In OTAs, I was running with the twos [second string], and the end of the veteran minicamp, I was running with the ones a little bit, so coming into fall camp I had a good sense that I would be competing for the job.

"When he [linebackers coach Mark Collins] told me I was No. 1, I said, 'OK, now it's time to buckle up.'"

Jacobs won the job -- beating out second-year players Blair Brown and Donald Payne and first-year player Brooks Ellis, among others -- because of how quickly he learned the Jaguars' defense. So quickly, in fact, that linebacker Myles Jack can't stop raving about it.

"Leon has been awesome," Jack said. "No. 1, he knows what he's doing. That's the coolest thing. Coach [Collins] will ask him a question in meetings and he'll be spot-on, no hesitation. So Leon is very bright, very intelligent. You can tell he goes home and he studies at night. He looks the part, so, very excited to see what ends up happening with him.

"... Not only is he in the classroom showing it, but he's on the field executing. He's very far ahead. He's further ahead than I was."

"Leon is very bright, very intelligent. You can tell he goes home and he studies at night." Jaguars linebacker Myles Jack on rookie Leon Jacobs

Because of the NFL's graduation rule -- which says players who attend schools with final exams that conclude after May 16 cannot participate in any activities other than the three-day rookie minicamp until after the school's final exams -- Jack missed all of the Jaguars' organized team activities during his rookie season out of UCLA in 2016. That made picking up the defense a lot harder.

Jacobs was not affected by that rule and already has gotten really good at one of the tougher aspects of the defense.

"He's out there communicating like me and Telvin [Smith], and the cool thing is he's kind of feeding off me and Telvin, so the more he hears us talking, the more he's talking and saying the right things," Jack said. "It's a breath of fresh air, you know what I mean? Instead of being like, 'Oh, OK, I've got a rookie. I've got to kind of worry about him, tell him what to do, make sure he knows what to do.' Leon is spot-on. I don't have to worry about him."

The strongside linebacker is a position that will be on the field for roughly 30 percent of the snaps, but it's still an important part of the Jaguars' base defense. The 6-foot-1, 246-pound Jacobs will line up closer to the ball, often adjacent to the tight end. The pre-snap keys and reads are different from middle and weakside linebacker, and he'll have more pass-rush and coverage duties.

So far, though, he's handled it pretty well, which is why defensive coordinator Todd Wash has no problem making Jacobs -- and not defensive tackle Taven Bryan, receiver D.J. Chark, safety Ronnie Harrison or offensive tackle Will Richardson -- the first of the team's rookies to start.

"We are seeing some real good things," Wash said. "Obviously, we are looking for consistency out of him, but we are excited with where he is at, at this time."

In the starting lineup.