The Pittsburgh Steelers were a focal point of the NFL offseason, as the world awaits whether or not quarterback Aaron Rodgers will sign with them. The Steelers, predictably, focused on shoring up their defense, and they took a chance on former Kansas City Chiefs safety Juan Thornhill, who is coming off a two-year stint with the Cleveland Browns.
While Thornhill took time out of his day on Tuesday to seemingly call out the Browns for signing former Steelers safety Damontae Kazee to replace him, he may need to worry about making the Steelers Week 1 roster. There is one player worth keeping an eye on, and that's undrafted free agent Sebastian Castro out of Iowa.
Juan Thornhill may not be a lock to make Steelers roster
Thornill is coming off of a 2024 season with the Browns in which he posted a career-high 14 missed tackles and 22.6 missed tackle percentage, per Pro Football Focus. There's no sugarcoating it, the tackling was bad, as evidenced by his 45.0 grade for tackling. Not the greatest numbers for a safety, but that didn't prevent the Steelers for taking a shot on Thornhill to reboot their secondary. But, that shouldn't mean Thornhill is a lock, as he's only signed for a one-year, $3 million contract.
Meanwhile, Castro has a bunch of hype surrounding him, despite going undrafted. Ben Cooper of Pro Footbal Focus listed Castro as one undrafted free agent to keep an eye on on the Steelers, due in part to his ceiling.
"The Steelers’ defensive cornerstones are locked in — T.J. Watt, Cam Heyward and Minkah Fitzpatrick among them — but the unit still has room for younger players to step up in the secondary.
"After posting the third-best PFF overall grade (91.2) among college football cornerbacks in 2023, Castro endured some regression in 2024. He allowed five touchdowns in coverage this past season after surrendering just three in the previous three years combined. But if Castro can do enough this offseason to make the roster, his ceiling would give the Steelers a valuable piece at box safety."
During his five seasons playing for the Hawkeyes, Castro was named Second-team and Third-team All-Big Ten in 2023 and 2024, respectively. Through those five seasons, Castro recorded 163 combined tackles (113 solo, 50 assisted), 14 tackles for loss, 14 passes defended, five forced fumbles, and four interceptions.
We'll see what transpires throughout the spring and summer. But as we all know, there's always a chance a rookie leaves a strong enough impression on the coaching staff that they can take a spot on the starting lineup away from a veteran player. Castro is a name for the Steelers fanbase to keep an eye on.