TAMPA, Fla. -- Big changes are coming to the Tampa Bay Buccaneers' defense in 2019. After nearly 30 years of being a predominantly 4-3 defense, the Bucs are expected to use a hybrid 3-4 base defense (three defensive linemen, four linebackers) under new head coach Bruce Arians and defensive coordinator Todd Bowles.

Arians said last week during his introductory news conference that the Bucs would "adapt to what the players do best," and Bowles agreed. The former New York Jets head coach said he had not had a chance to view the Bucs' game tape, but he noted he had spent half of his career coaching a 3-4 defensive scheme and the other half a 4-3 scheme.

Tampa Bay fans can expect a much different look from the defense next season, and here's what you should know before offseason workouts begin:

Bucs will be a one-gap defense

A one-gap defense is different than a traditional 3-4, which typically asks players to play in a two-gap. In that scheme, defensive linemen try to occupy their blockers and allow players on the back end to penetrate. "We're going to attack," Arians said.

For example, the Bucs' 2018 first-round pick, Vita Vea, won't be a space-eating nose tackle here. Instead, he will go up the field and get after the quarterback, much of it similar to what he's done in Tampa already.

Gerald McCoy, who has spent all nine of his NFL seasons in the Bucs' 4-3 scheme, is to make $13 million next year (none guaranteed) if he remains on the roster. Given that the Bucs are about $16.5 million under the salary cap going into 2019, there is a real chance he won't return.

"We have a lot of tough decisions to make," general manager Jason Licht said when specifically asked about McCoy. "A lot of people have a lot of tough decisions to make."

One player who won't be going anywhere next season is Jason Pierre-Paul, who had 12.5 sacks this past season. He would line up as a rush-end, which is really a hybrid five-technique defensive end/outside linebacker standing at the line of scrimmage.

"We tried to get Jason Pierre-Paul really, really hard in Arizona," Arians said. "And we got Chandler Jones and he's [produced 41 sacks] the last three years, so [Pierre-Paul] fits extremely well because he rushes the passer."

The real question is, can Pierre-Paul be as effective standing up after spending his whole career with his hand in the dirt?

They will blitz often

Whether it was when he was with the Jets or the Arizona Cardinals, a Bowles-led defense will blitz often, and those blitzes have been effective.

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From 2015 to 2018, Bowles' Jets blitzed 936 of 2,501 dropbacks (37.4 percent), second most in the league, according to ESPN Stats & Information. Those blitzes resulted in 125 quarterback hits and 26 interceptions, ranking third most and second most, respectively, of any team when blitzing.

When he was the defensive coordinator of the Cardinals from 2013 to 2014, Bowles' defense blitzed 620 of 1,333 dropbacks (46.5 percent), which was the most in the NFL. Quarterbacks were contacted on 92 of those dropbacks and threw 17 interceptions, both numbers more than any other team in the league.

"Most of it was the illusions of pressure, as opposed to pressure itself," Bowles said. "A lot of guys came free. We had some good athletes on that team and they made me look good."

One of Bowles' favorite blitzes is the triple A-gap pressure, where three defenders (usually two linebackers and a safety) attack the space between the center and guards on both sides.

From 2016 to 2018, the Bucs blitzed just 418 of 1,792 times (23.3 percent of dropbacks), so this will be quite a change. It also will mean the secondary will be much more vulnerable on the back end, but the gist of this scheme is "high risk, high reward."

What happens with David?

Lavonte David's future could be one of the Bucs' most important offseason decisions. He is a prototypical 4-3 weakside linebacker -- smaller, quicker and instinctive. David is arguably the Bucs' most athletic player and best tackler. He's also due to make $9 million next season, none of which is guaranteed, which might push him to change teams because of the scheme change.

While Arians generally allows Bowles to run the show on defense, he does believe there's a spot for David because he can blitz, tackle and cover. Linebackers who can truly cover receivers are valuable commodities in today's NFL.

"Oh, I think he'll be a great inside linebacker for us," Arians said of David. "Our stack backer -- basically the same thing he's played -- it's not really any different."

A "stack" linebacker typically plays behind the three-technique and away from the tight end, on the weakside of the formation.

David gives them a ton of options here. He was the jack of all trades under former coach Greg Schiano, finishing with 7.0 sacks, five interceptions and 10 pass breakups in 2013.

Expect versatility, adaptability and aggressiveness

Bowles' history suggests he also will be unpredictable. When he was facing the Dallas Cowboys in 2014, he converted his Cardinals' defense from a 3-4 and unveiled a 4-3, believing it was better schematically. Arizona held DeMarco Murray to 79 total rushing yards and won 28-17.

When Cardinals linebacker Darryl Washington was suspended, Bowles took strong safety Deone Bucannon and created a "moneybacker" role for him. He did the same with J.J. Wilcox when Bowles was with the Jets last season.

You can also expect Bowles' cornerbacks to play more aggressively, giving far less cushion than they had under Mike Smith and his off-coverage scheme. Bowles will have his corners press, too (although not all the time, and at times he was criticized in New York for not doing it enough). He favors longer corners, and that bodes well for Carlton Davis.

Although Vernon Hargreaves III doesn't have Davis' 6-foot-1, 206-pound frame, he could see a career resurgence being able to use his physicality to disrupt receivers' routes the way he did at Florida.

No matter what personnel decisions are made, the Bucs' defense is sure to look much different to fans than the "bend but don't break" scheme they'd come to know for decades.