HOUSTON -- Just days before Houston's 2016 season-opening upset of Oklahoma, when the college football world would be introduced to Ed Oliver, the then-18-year-old was already making his coaches shake their heads at his athletic feats in practice.

While practicing a Sooners play they'd scouted -- a quick pass to the running back in the flat, designed to get speedy Joe Mixon out into the open field -- they assigned Oliver, a defensive tackle, to "spy" the running back. So when Houston quarterback Greg Ward Jr. motioned running back Duke Catalon over and Catalon sprinted toward the sideline, imagine the surprise when the 280-pound Oliver beat him to the ball.

"When we ran this [in practice], we widened our back out all the way behind the tackle, because we knew [Mixon] could run," Houston coach Major Applewhite said. "And [Oliver] ran down Catalon's hip, and the ball was thrown perfectly by Greg, and he knocked it down ... like he was in man coverage."

When the Sooners actually ran the play during their meeting, Oliver didn't get there quite that quickly but did sprint from one side of the field to the other to catch Mixon -- who runs a 4.5 second 40-yard dash -- for a meager 2-yard gain.

A defensive tackle covering a running back on a pass play might sound unwise, but with Oliver, anything is possible.

"Athleticism and effort," Applewhite says, reviewing the play from his office. "He's a unique player because of his athleticism. There's a lot of [defensive tackles] that can sit there and plug."

For the last two seasons, Oliver has terrorized many an offensive backfield. In that time he has amassed 39.5 tackles for loss, more than any other player in their first two seasons in recent memory (nobody in the past five years has compiled that many in their first two years). He's second among FBS defensive linemen in pass breakups in that span. In December, Oliver became the first underclassman (freshman or sophomore) to win the Outland Trophy.

"I think he's the most disruptive defensive lineman I've seen in college football," said former Rice coach David Bailiff, who coached against Oliver last season. "He's as close to the Tasmanian Devil on the football field that I've ever seen."

When it comes to pure football talent, there's no doubting Oliver's credentials. That's why Oliver is at least on the periphery of the way-too-early discussion of Heisman Trophy candidates. Whether he'll have a realistic shot at the hardware is another discussion entirely.

"We have to see what he does on the field [this season]," Applewhite said. "I think he deserves to be in the conversation. If the award is what it says it is, which is the best player in college football, then he deserves to be in the conversation."

In the 83-year history of the award, only one player from a primarily defensive position has won it: Michigan cornerback Charles Woodson in 1997. Only 18 defensive players have finished in the top five in Heisman voting, according to ESPN Stats & Information. Ten of those were defensive linemen, but only two defensive linemen have finished in the top five since 1990.

Will a defensive player ever win it again?

"In my personal opinion, no," said former Nebraska defensive tackle Ndamukong Suh, now with the Miami Dolphins. "And the reason why I say that is because I think there has been some elite guys, not including myself, that have given it some good shots and had good bodies of work to do it, but I think just because it's such a heavily offensive-oriented and quarterback-oriented and running back-oriented type of award, it's very difficult."

Suh, who finished fourth in the 2009 voting and is the most recent defensive lineman to finish in the top five, had a strong case. He also had a "Heisman moment," by nearly lifting Nebraska to a Big 12 championship with 12 tackles, six for losses and 4.5 sacks in a 13-12 loss to Texas that year. Alabama running back Mark Ingram wound up winning the trophy that season.

Texas quarterback Colt McCoy, whom Suh threw around like a rag doll when they met, finished third, a spot ahead of Suh "even though I put a good thrashing on him in the Big 12 championship," Suh said.

Former Houston quarterback Andre Ware, who won the Heisman in 1989 and voted for Suh, said that illustrates how difficult it is for a defensive player.

"When that happens, then it's tough for it to ever happen," Ware said. "You get that one shot down ... then you've made it an offensive award. [Suh] deserved to win it in my opinion. But that makes it tough."

Only six players who have won it didn't play in the offensive backfield. The frequency at which quarterbacks and running backs touch the ball is a big reason they win it most often.

"It's different when you have a chance to touch the football every snap. That alone creates the attention that you're going to get," said Arizona coach Kevin Sumlin, who coached 2012 Heisman winner Johnny Manziel. "Really that's a quarterback and a running back. It's difficult for even a receiver to win it.

"What are we voting for? Is the Heisman trophy the best player in the country? Is it the best catalyst on a team in the country? Those are two different things. ... Is this guy the best player on the best team in the country? That's happened before, too."

Coaches and former players acknowledged that being a part of a great team is a virtual necessity. Having a big performance on a big stage helps, too. That can be a challenge for a defensive lineman, especially considering how creative coaches get to minimize an individual player's impact.

"You can game plan around a player," said Baylor coach Matt Rhule, who played against Woodson's Michigan team while he was at Penn State. "You can do a lot of speed, no-huddle, up-tempo stuff. You can mitigate some of the defensive player's ability to affect the game just by getting the ball out of your hand before he gets to the quarterback."

Oliver has experienced some of that at Houston, but the Cougars' staff has been creative about where he lines up and the assignments he gets to maximize his impact. So far, it has been successful. The main thing that slowed down Oliver was a knee injury last season that kept him from playing at full strength for the better part of five games. Still, he finished with 73 tackles, 16.5 for loss, 5.5 sacks, seven quarterback hurries, two forced fumbles and a blocked kick.

"[The injury] took away from my mobility, moving sideways a little bit," Oliver said. "I'm upset at the way I played last year. It really makes me mad, watching film, knowing what I can do and what I was limited to doing."

The junior-to-be says that he's at 100 percent now. After winning the Outland Trophy, he's coming for more hardware.

"I can't stop there," he said. "I need to go back and win the Nagurski and the Bednarik. I need both of them."

If he comes up short, it won't be for lack of effort or physical gifts. Applewhite said Wednesday morning that Oliver challenged one of the team's linebackers in a six-station drill -- which included a 60-yard shuttle and a short-shuttle, among other agility drills. Unsurprisingly, Oliver won.

Given his production and ability, 2018 figures to be Oliver's last in college. He hopes to be not just a high draft pick but No. 1 overall. As for the Heisman, Oliver said while he doesn't expect to be there, being in the conversation would be special "for the city and for the guys I play with and the guys that helped me get there, the coaches for believing me and trusting in me."

What does he think would it take for him to get there?

"I'd love to be there, but I doubt I'd win," he said. "I gotta pass for a touchdown, catch a touchdown, run for a touchdown, get some fumbles for touchdowns, picks for touchdowns. It's all about how much you score."

Oliver did run for a touchdown lining up as a goal-line running back in Houston's bowl game last season. Could he lobby for more of those touches?

"You never know," he said.