The Pittsburgh Steelers can’t catch a break. This preseason, they were focused on gauging their depth and refining their new defensive foundation. And Derrick Harmon was squarely at the center of it. The first-year defensive tackle had dressed for each of the three exhibition contests. Thursday evening in Charlotte, he was still among the last of the starters hanging in there late in the game, but then, in the quiet that hushed the stadium, Harmon’s night unraveled. He got injured.

The play followed as Harmon bull-rushed guard Brandon Walton. Walton knocked him to the ground as Harmon made the turn, and the rookie landed hard on his right side. The pressure blitzed Panthers quarterback Jack Plummer into a hasty throw that James Pierre intercepted in the end zone. But the joy was short-lived. Harmon stayed down, clutching his knee. The cart came, teammates swarmed, and the atmosphere within Bank of America Stadium thickened. Several minutes later, the Steelers’ first-round draft pick was formally announced out for the game with a knee injury. It was a setback that no one in Pittsburgh wanted to endure.

The Steelers had brought Harmon as a replacement for veteran captain Cameron Heyward in future years. They made the draft based on his ability to do it all and his raw physicality. His playing time during the preseason demonstrated the confidence the coaches already had in him. The injury not only derailed his climb but also had the potential to ripple into the team’s defensive game plans before Week 1. His injury is a potentially significant development ahead of roster cutdown day on August 26.

Head coach Mike Tomlin gave nothing away in his halftime press conference. “I don’t have an update at the moment,” he told sideline reporter Missi Matthews. “He is being evaluated.” That answer just increased the mystery looming over the locker room. What’s worse? The concerns didn’t stop there with Harmon.

The Steelers are also battling through other injury issues. Wide receiver Brandon Johnson, who had five receptions for 28 yards and a touchdown this preseason, was listed as questionable to return with a foot ailment. Rookie quarterback Will Howard, who was battling a hand problem, didn’t suit up for the Carolina game. Wide receiver Calvin Austin III, who had a sore belly, also missed the game, perpetuating an alarming trend for Pittsburgh’s offensive depth with the regular season approaching.

How Harmon’s injury affects the Steelers’ defensive strategy

The Steelers’ defense was to be built on a combination of old and new this season. Cameron Heyward remained the veteran elder, Keeanu Benton entered as a disruptive nose tackle, and Harmon entered to complete the setup. That configuration gave Pittsburgh a strong interior to pair with T.J. Watt‘s edge domination. With Harmon’s status now uncertain, the Steelers may be forced to reshape their depth chart sooner rather than later. Looking at the rotation on defense, Isaiahh Loudermilk can be the player to assume Harmon’s workload.

Loudermilk is a solid, unflashy mainstay who has seen rotational snaps in past seasons and could be asked to step into the void. Behind him are Esezi Otomewo and Logan Lee, but neither has Harmon’s first-round background or short-term potential. It’s a situation where the depth emphasis from the coaching staff this preseason will be tested.

The rookie DT isn’t only expected to contribute; they view him as a building block for the future. His ability to occupy blocks and harass the pocket was designed to get Heyward more favorable matchups and give Watt cleaner avenues. Without Derrick Harmon, the Steelers’ line could be more vulnerable in the run and less effective in pressuring the pocket. The timing makes it sting all the worse. Hopefully, it’s nothing major, and he’ll be ready to hit the field come Week 1.