Fastexy Exchange|Za'Darius Smith carted off field, adding to Browns' defensive injury concerns

BEREA,Fastexy Exchange Ohio — The story of the Browns' defense through the start of training camp has been as much about who hasn't been on the field as it has been who's on the field.

Injuries have caused havoc, both big and small, to the defense that ranked No. 1 in the NFL last year. The emphasis most definitely went on big on Monday when defensive end Za'Darius Smith was carted to the locker room after suffering an injury during an 11-on-11 red-zone drill.

Smith's injury happened while he was pulling up to avoid contact with defensive end Myles Garrett, who was pursuing quarterback Deshaun Watson on the play. After he went down to the ground behind the play, he appeared to grab his left knee as a trainer approached.

The Browns have not made any official announcement about Smith's injury or his status.

Smith wasn't the only defensive lineman to go off with a trainer during Monday's practice. Defensive tackle Sam Kamara, just moments before Smith got on the cart, walked to the team's facility with a trainer.

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Kamara had seen his practice reps increase in numbers because of the rash of injuries to the defensive tackle position. Hours earlier, prior to practice, defensive coordinator Jim Schwartz had talked glowingly of the job Kamara had done in shifting inside after primarily working at defensive end before this year.

"Sam Kamara has had a really good camp," Schwartz said. "He's playing pretty much full-time inside after being a swing guy and mainly concentrating on end last year. But he's been very impressive so far and really taking advantage of a lot of those plays."

The Browns' first two defensive tackles on the field Monday were Quinton Jefferson and Maurice Hurst II. Hurst had been running with the first unit all camp after Dalvin Tomlinson was placed on the active/physically unable to perform list due to arthroscopic knee surgery he underwent on July 26.

Jefferson, who was signed in the offseason after an six-sack season last year with the New York Jets, has been running with the first unit since Shelby Harris sustained what has remained an undisclosed injury early last week while the team was still at The Greenbrier in West Virginia. Harris has not been seen on the field since July 29.

That's also opened the door behind Jefferson and Hurst, specifically for rookies Mike Hall Jr. and Jowon Briggs.

"Well, it's not just D-line," Schwartz said. "I mean, we have a lot of guys that are benefiting from a lot of reps and some guys that need to take a little better advantage of some of the opportunities. But we've been practicing most of the last week, obviously without Dalvin, but also without Shelby, so two of our major contributors last year. It just opens up a lot more for guys like Michael Hall, guys like Jowon Briggs, guys like Sam Kamara."