OXNARD, Calif. -- Eyebrows were raised when Dallas Cowboys coach Brian Schottenheimer talked about the weight of defensive tackle Mazi Smith at the start of training camp.
"He's right at 300 [pounds]," Schottenheimer said.
The largest issue around the Cowboys' defense in recent years has been its effectiveness against the rush. Dallas drafted Smith in the first round in 2023 to help shore up that part of its defense. At Michigan, Smith was the prototypical run stuffer, checking in at 323 pounds.
"I've been about 305 the last few seasons," Smith said. "Right now I'm about 310, 315. It's whatever weight feels good. Your body changes and then you can put on lean mass differently. You don't want people to look at you and tell that you [weigh] this much. You want to be explosive. You want to be dense. You want to have all the weight in the right places."
But as a rookie, when Dan Quinn was defensive coordinator, Smith's weight dipped late in the season to below 300 pounds. The Cowboys finished with the 16th-ranked run defense. Last year, with Mike Zimmer as the DC, the Cowboys wanted him bigger. He was listed at 328 pounds. And the Cowboys finished with the 29th-ranked run defense.
Smith, who is listed on the team's roster at 315 pounds, now has his third defensive coordinator in as many years -- and Matt Eberflus is bringing another change to how the Cowboys will try to stop the run.
What is the key to a successful run defense for Eberflus?
"Teamwork," Eberflus said. "Yeah, teamwork. It's not just the inside guys. It's not just the outside guys. It's everybody. To have an elite run defense, it's going to take everybody. ... And that starts with ... good tackling when our corners tackle. And that's important. Because all the schemes nowadays make your corners tackle. Our guys will be a good tackling bunch, and we work on that daily."
Eberflus' history suggests size doesn't matter. OK, maybe it matters to some extent, since Eberflus acknowledged the defensive tackles do need some size.
"The double-teams happen on the inside, as we know, so you're talking about 600-plus [pounds] versus 300," Eberflus said, "so those guys do have to be stout inside there to be able to hold and anchor the point inside the middle of your defense."
Said Smith, "Football is football is football. And the nose [tackle] plays one way. You've got to be the strongest person on the field at any given moment."
In eight of the past 12 years that Eberflus has been around a 4-3 defense -- as a linebackers coach, coordinator or head coach -- his units have ranked in the top 10. Three times, he has had the No. 1 or No. 2 run defense, including 2016, when he was the Cowboys' linebackers coach.
The Cowboys' starting defensive tackles that year were Terrell McClain (300 pounds) and Maliek Collins (310). Only four times did Eberflus have a defense in which both tackles weighed more than 300 pounds.
The Cowboys have seven defensive tackles in training camp. Four weigh at least 300 pounds, with rookie Jay Toia the heaviest at 340. Osa Odighizuwa, who will start next to Smith, weighs 285.
"You've got to have guys that hold up their guys," said Solomon Thomas (285). "A guy that's 280 and a guy that's 320 can hold up the game the same. They can also get blown back the same. It just depends on pad level, violence and their technique. That's really all it is. So I think it's more about your discipline, your technique, your heart and your violence more than size."
The first preseason game against the Los Angeles Rams wasn't the best of starts for the run defense. The Rams rushed for 181 yards on 38 carries and two touchdowns, although Schottenheimer noted most of the damage came in the second half. Although Smith played, a lot of the other starters in the front seven did not.
"We gave up 2-point-something in the first half, run-defense-wise [actually 3.1 yards per carry], and in the second half we just kinda didn't tackle very well," Schottenheimer said.
The Cowboys play in a division that had the second- and third-ranked run offenses last season (Philadelphia Eagles, Washington Commanders). Running back Saquon Barkley had more than 2,000 yards for the Eagles. Washington was led by quarterback Jayden Daniels. Four of the Cowboys' other 2025 opponents had run games that were in the top half of the league last season.
In 2024, the Cowboys allowed more than 140 rushing yards in a game eight times, including 274 to the Baltimore Ravens.
Eberflus has to rebuild not just the front but the confidence of the group. The holdovers in the front seven expected to play a big role in 2025 are Smith, Micah Parsons, Sam Williams (who missed last season with a knee injury), Marshawn Kneeland, Osa Odighizuwa and Marist Liufau. Linebacker DeMarvion Overshown is expected back from a torn right ACL, MCL and PCL in November.
Through free agency, trade or the draft, the Cowboys added Dante Fowler Jr., Donovan Ezeiruaku, Thomas, Toia, Payton Turner and Perrion Winfrey up front, and Kenneth Murray Jr. and Jack Sanborn at linebacker.
"Doing your job is No. 1," Sanborn said of what makes a good run defense. "Obviously physical play, getting hats to the ball and swarming the ball carrier, especially in certain defenses you play. I mean, everybody's got a job to do, and sometimes you're not the one going to be able to make the play, but you're going to set up the guy next to you to make that play."
Owner and general manager Jerry Jones is not ready to write Smith off, using legendary Cowboys coach Tom Landry's mantra that linemen need three years before one can make a true evaluation of them. Smith started every game last year and had some positive moments, just not enough of them.
Because of his first-round status, he takes the brunt of the criticism for a poor run defense, but Jones thinks the run defense will be about the group in 2025.
"I think we're going to use him in a way that really [fits] his skills," Jones said. "He's quick, but he's strong. I think the way Flus has got him lined up here is going to help him as well. But we've got a good rotation in there with good size. And I'm anxious to see what that is."
Will this be Smith's breakout season?
"What else it going to be?" Smith said with a smile.