Dolphins add defensive end Seth Coleman-Lyles to 90-man roster, waive Mason Reiger with injury designation

The Miami Dolphins made a roster adjustment to their defensive line on Tuesday by signing defensive end Seth Coleman-Lyles to the team’s 90-man roster. The move was paired with waiving defensive end Mason Reiger with an injury designation, a corresponding step that typically changes how the team manages the early preseason roster picture.

Coleman-Lyles’ arrival gives Miami another option at defensive end, a position group the Dolphins have been working to stabilize through a mix of draft-and-develop prospects and veteran depth. With the 90-man roster, teams generally aim to carry enough personnel to cover multiple defensive packages and to evaluate pass-rush reps, gap control, and run defense across a full preseason workload.

For Reiger, the transaction matters in a different way. When a player is waived with an injury designation, it indicates the player is dealing with an injury that affects his availability, and the waiver process can determine whether he returns to the team, is claimed by another club, or follows a different path depending on how the league treats that designation. The Dolphins’ decision to pair the move with Coleman-Lyles suggests they wanted immediate roster flexibility while continuing to assess defensive end depth.

From the Dolphins’ perspective, signing Coleman-Lyles is a low-to-moderate risk way to add another body for training camp and preseason practices, especially for a position that can require specialized coaching attention. Defensive ends are judged on more than raw effort, they are expected to understand hand-fighting rules, leverage at the point of attack, and the different rushing lanes assigned in various schemes. That kind of evaluation is often the central purpose behind 90-man signings in August.

The bigger backdrop is that the Dolphins are working within a league-wide roster churn period, where teams frequently adjust personnel as players get reps and staff identify the right mix for later roster cuts. Moves like this also reflect the reality that injuries, performance, and matchup needs can change quickly, forcing teams to rethink who offers the best combination of upside and readiness.

It is also worth noting that preseason roster decisions can have a downstream effect. A new signing can influence practice group dynamics, deepen competition for rotational snaps, and potentially change which players are prioritized for keeping later into final cut deadlines. Meanwhile, injury-designated waiver decisions can report that a team believes a player may not be immediately available, or that roster timing makes it prudent to free up a spot while evaluating other options.

What to watch next is whether Coleman-Lyles takes hold of the defensive end rotation during upcoming practices and preseason appearances, and whether the Dolphins’ defensive line depth chart clarifies in the weeks ahead. Equally, Reiger’s waiver outcome will be something Miami and its fans will track, since the path his designation creates can determine whether he stays in the organization or moves on.