Dolphins’ mystery training camp injury befalls key veteran

The Miami Dolphins encountered a concerning training camp setback Wednesday when head coach Jeff Hafley announced that defensive lineman Zach Sieler is week-to-week with an undisclosed injury.

Sieler enters his ninth NFL season as an established presence on Miami’s defensive front. The 30-year-old started all 17 games last season, recording 47 tackles and 5.5 sacks while remaining one of the Dolphins’ most dependable defenders.

His absence creates another complication as Hafley continues installing his defensive system during his first training camp as Miami’s head coach. Sieler’s combination of experience, durability, and interior production makes any extended absence significant for a defense preparing for the regular season.

In an article published Wednesday morning, Pro Football Talk’s Myles Simmons reported the latest Dolphins injury news following Hafley’s press conference. While the coach gave a general designation for Sieler’s recovery, he did not specify the nature of the injury.

“Head coach Jeff Hafley told reporters in his Wednesday press conference that defensive lineman Zach Sieler is considered week-to-week.

Hafley did not disclose the nature of Sieler’s injury.”

The Dolphins have not provided a definitive public timeline for Sieler’s return. They will likely keep him out of Friday’s preseason game vs. the Washington Commanders, making his progress worth monitoring as the team moves closer to the 2026 NFL season

Sieler has appeared in 108 career games with 82 starts between time with Miami and the Baltimore Ravens. The Dolphins claimed him off waivers from Baltimore in December 2019, and he has since developed into a fixture along their defensive line.

His recent production reinforces the significance of the setback. The veteran defensive lineman started every game in the 2025 season after recording 10 sacks in each of his previous two seasons.

For now, the Dolphins must prepare their younger defensive linemen for increased work while Sieler recovers. The undisclosed nature of his injury creates uncertainty, but the week-to-week designation suggests Miami will evaluate his condition as training camp continues.