The Pittsburgh Steelers always roster a handful of special-teams focused players. That was a theme under Bill Cowher. Linebacker Clint Kriedwalt, wide receiver Sean Mory, cornerback Chidi Iwuoma. It’s proven true under Mike Tomlin. Wide receiver Darrius Heyward-Bey, safety Robert Golden, and linebacker Terence Garvin. Miles Killebrew is one of those players on the team’s 2025 roster, likely to become a special teams captain for a fourth season. Rookie safety Sebastian Castro isn’t currently in that position but by 2026, he might be.
There’s plenty of Killebrew in Castro’s game. Physical and plucky safeties who didn’t test well but show out better on tape. Killebrew was an awkward hybrid from a small school. Castro is smaller but a similar athlete (he registered just a 4.37 RAS). Their strengths are in their physicality, tackling, and intensity.
Killebrew can still play. But he’s 32 and entering the last year of his contract extension. Turning 33 before next season begins, 2025 could be his last. Like any skill position, special teamers (specialists like kickers, punters, and snappers aside) don’t often play into their mid-30s. Killebrew’s already beaten the typical shelf life.
That means looking for his replacement. Castro fits the bill. An intriguing UDFA from Iowa, Castro surged throughout the summer and showed up inside stadiums. Always around the ball with hit power and reliable technique, he even spent some of his time working at Killebrew’s primary position. Castro logged time as the personal protector of the punt coverage team, the quarterback of that unit. The player in charge of communicating the number of potential rushers, the blocking scheme (usually declaring which way the PP and LS will block), and snapping the ball since the punter is too far away to vocalize that call.
In the preseason opener, watch Castro (No. 29) run down this punt and make a strong open field tackle from his upback slot.
Castro is set to spend his rookie year on the practice squad. Only injuries could open the door for him to be elevated. But if Castro looks trustworthy in practice and grows behind-the-scenes, he could take over for Killebrew next year. Castro would be in his second of three years on his rookie contract and still be a restricted free agent when his deal is over. He could be the next cog in the Steelers’ special teams machine and become a relevant player in the 2026 roster.
