Juan Thornhill, who came in as the replacement for Minkah Fitzpatrick, has now been replaced himself. The Pittsburgh Steelers head coach, Mike Tomlin, showed him the door just months after signing him. The move wasn’t exactly shocking, but the timing is a bit surprising, coming right after the trade deadline and with the Steelers’ secondary still thin.

However, Thornhill said goodbye with just four words. “It’s been real, Pittsburgh✌️🙏,” the safety posted on his Instagram story.

Thornhill’s Pittsburgh chapter was short-lived and uneasy. Despite starting one game in nine appearances, he often found himself on special teams more than defense. Even when injuries piled up, Fitzpatrick traded away, DeShon Elliott out for the season, and both Chuck Clark and Jabrill Peppers sidelined, Tomlin still kept Thornhill off the field.

Instead, the Steelers plugged in Kyle Dugger after only two practices and even shifted Jalen Ramsey to an unfamiliar safety spot. That signaled everything. Thornhill was no longer part of the plan.

The Kansas City Chiefs drafted Thornhill in the second round of the 2019 NFL Draft. Even after four years with Kansas City, where he recorded a career-high 71 tackles in 2022, his contract was not renewed. So, he signed as a free agent with the Cleveland Browns on a two-year deal. In early 2025, Thornhill ultimately signed a one-year, $3 million contract with the Pittsburgh Steelers.

But Thornhill’s production didn’t match his résumé. He logged 38 tackles, forced one fumble recovery, and broke up a single pass. Not terrible, but far from what Pittsburgh expected. So, now Tomlin moves on with a familiar name in his spot.

Mike Tomlin brings back Sebastian Castro

The Steelers claimed Sebastian Castro off waivers after the Tampa Bay Buccaneers released him. Ironically, Castro began the year in Pittsburgh before Tampa snatched him up on September 30. Now he’s back, this time with a three-year, $2.99 million deal and $25,000 as a signing bonus to prove the team sees potential.

Castro might be untested in the NFL, but his college career at the University of Iowa was anything but ordinary. During 53 games for the Hawkeyes, he stacked up 163 tackles, 14 for loss, plus 18 passes defended and 5 forced fumbles. 

He plays fast, hits hard, and fits the Steelers’ defensive identity. That’s what Mike Tomlin seems to want: young energy and flexibility over struggling veterans.

The deal is straightforward: one roster out, one back in. Thornhill’s departure clears space, but more importantly, it resets expectations in a defense that’s been patched together all season.