First-year defensive coordinator Brian Stewart is leading the Terrapins’ transformation to a 3-4 defense. (Jonathan Newton/The Washington Post)

In vogue in the NFL over the last decade, the 3-4 scheme comprises three defensive linemen and four linebackers along the front seven. The outside linebackers generally are asked to apply pressure on the quarterback, but their assignments may vary depending on down and distance.

The man in charge of ensuring the seamless transition is defensive coordinator Brian Stewart, who is in his first year with the Terrapins after serving in the same capacity for two seasons with the University of Houston.

“I think the main thing is to get everyone to buy in that you’ll have an opportunity to make plays,” Stewart said. “I think in the 3-4, the D-linemen get scared, ‘Oh, I’m not going to get the opportunity to get on the edge and pass rush,’ or, ‘I don’t get the opportunity to run inside and get a tackle for loss.’ That’s not true.”

The defensive makeover includes moving Joe Vellano to defensive end. The senior was second-team all-American last season at defensive tackle, where he led all Football Bowl Subdivision defensive linemen in tackles per game (7.8). Vellano had started 24 consecutive games at defensive tackle.

With senior A.J. Francis (Gonzaga) slated to start at nose tackle, there is competition for the starting spot at the other defensive end. Sophomores Andre Monroe and Keith Bowers (St. John’s) are in the mix, as is Justin Anderson, although as of Tuesday the junior had not passed his conditioning test and was held out of practice.

Another intriguing piece to the 3-4 is a healthy Kenny Tate. The senior missed all but four games last season after a knee injury that required surgery, but the All-Met from DeMatha said earlier this week he was healed.

Tate, who has one year of eligibility remaining thanks to a medical waiver, was an all-ACC selection at safety as a junior. Last season he moved to the Star, which is a hybrid position with elements of linebacker and safety.

In 2010, Tate led the Terrapins in solo tackles (58) and was second in overall tackles (100). He also was first in the conference with four forced fumbles, including a memorable stop of then-Navy quarterback Ricky Dobbs on fourth down and goal from inside the 1 to seal a 17-14 win.

“The biggest thing that Coach Stewart talked to us about is, the 3-4 scheme, you don’t know where people are coming from,” said senior linebacker Demetrius Hartsfield, who was honorable mention all-ACC last season. “You never know. All seven could be coming. That’s the biggest thing. It’s a lot of disguising.”

Last season, Maryland finished 108th in the country out of 120 FBS teams in total defense while running a more traditional 4-3 alignment. The Terrapins were 111th against the run and 75th against the pass, leading to the school buying out the remainder of then-defensive coordinator Todd Bradford’s contract.

Maryland Coach Randy Edsall then hired Stewart in January to stabilize a defense that returns all but one starter from last season. Among Stewart’s accomplishments with the Cougars included improving their scoring defense from 96th in 2010 to 35th last year.

Houston also finished in the top 15 last season in five defensive categories, most notably red-zone scoring, interceptions and tackles for loss.

“When you just take a look at our personnel, I think we’re better suited to do the things we want to do defensively” in the 3-4, Edsall said. “Our players picked up on it. It’s going to be good to be full strength, and hopefully we stay that way for a long period of time throughout the year.”