The Pittsburgh Steelers have claimed S Sebastian Castro off waivers, the team announced Monday. In a corresponding move, the team released veteran S Juan Thornhill.
Castro returns to the Steelers’ organization after signing with the team as an undrafted free agent in April. With the makings of a special teams ace, Castro showed promise of becoming the next Miles Killebrew. Pittsburgh waived Castro during final roster cutdowns but signed him back to the practice squad. The Tampa Bay Buccaneers poached him off the Steelers’ practice squad in late September, rostering him until waiving him over the weekend.
He appeared in one game for Tampa Bay, logging six special teams snaps in a Week 6 game against the Tampa Bay Buccaneers. He made one tackle.
We noted the possibility of Pittsburgh bringing Castro back. This time, it’s a waiver claim that will place him on the 53-man roster and occupy Thornhill’s spot. Castro will provide more gameday value.
Our camp notes on Castro were positive, and we noted him as a possible special teams standout. In our August evaluation, we wrote:
“An undrafted rookie out of Iowa and popular pre-camp sleeper, Castro was quiet over the first week. His play perked up throughout, and he shone brightest inside stadiums. Castro finished with 11 preseason tackles, proving to be a physical and reliable wrap-up player.
Castro knocked a couple passes away in coverage and a one-handed snag on Will Howard’s lone camp interception. However, true to the “football player” label attached to him, he became a different guy for in-game action. He trailed only ILB Carson Bruener in special teams snaps and worked as an upback on the punt team, the quarterback of the unit. Castro beat out Quindell Johnson for a spot on the practice squad. Castro could be Miles Killebrew’s special teams replacement next year.”
Pittsburgh’s dealt with a rash of safety injuries this season. Killebrew suffered a season-ending knee injury covering a kickoff in Week 6. Veteran SS DeShon Elliott has suffered multiple knee injuries, including one that currently has him on injured reserve. And Jabrill Peppers has missed the last two weeks due to a quad injury suffered during practice. Castro will provide short-term depth and special teams help, while potentially becoming a core special-teamer in 2026.
Thornhill had fallen out of favor defensively and failed to log a defensive snap the last two weeks. He also brought minimal special teams value.
Pittsburgh’s roster is back to 53 players. The Steelers will need to make a corresponding move should they activate rookie QB Will Howard from injured reserve. That decision is due by Wednesday.