Miami Dolphins defensive tackle Zach Sieler. Joe Nicholson-Imagn Images

Dolphins lock in defensive standout to long-term extension

By Adam Gretz | Last updated Aug 3, 2025 8:14 PM ET

It's been a lucrative weekend for some of the NFL's defensive tackles. Just one day after the Denver Broncos locked in Zach Allen on a long-term deal, the Miami Dolphins did the same with another Zach — Zach Sieler — and signed him to a three-year, $67 million extension that will now make him the highest-paid defensive player on the Dolphins roster.

Dolphins and DT Zach Sieler reached agreement today on a three-year extension worth up to $67.75 million, including $44 million guaranteed, per Drew and Jason Rosenhaus. Sieler had two years remaining on his deal and he now becomes the Dolphins’ highest-paid defensive player. pic.twitter.com/cJ1NtxGpbl
— Adam Schefter (@AdamSchefter) August 3, 2025

The Dolphins defense took a big step forward in 2024 and climbed to the top 10 in points allowed and the top four in yards allowed. They still struggled against some of the NFL's better teams, but it was a better unit overall and Sieler was a big part of that.

He's been a full-time starter the past three seasons and is coming off back-to-back 10-sack campaigns for the Dolphins.

He is going to turn 30 just after Week 1 of the season, but his game should age well throughout the contract extension.

It was a quiet free agent signing period for the Dolphins defense, mainly focusing on depth additions, but they did make one blockbuster trade by sending Jalen Ramsey and Jonnu Smith to the Pittsburgh Steelers for Minkah Fitzpatrick.

They also addressed the defensive line in the 2025 NFL Draft in a big way by selecting defensive lineman with two of their first three picks. That included first-round pick Kenneth Grant out of Michigan and fifth-round pick Jordan Phillips out of Maryland.

Adam Gretz

Adam Gretz is a freelance writer based in Pittsburgh. He covers the NHL, NFL, MLB and NBA. Baseball is his favorite sport -- he is nearly halfway through his goal of seeing a game in every MLB ballpark. Catch him on Twitter @AGretz

More must-reads: