Film Room: Sebastian Castro is a strong candidate to make Steelers roster as an undrafted free agent

257 players were chosen in last month’s NFL draft, over a span of three days and seven rounds. None of them were named Sebastian Castro.

And yet, while many of those players will ultimately fail to stick with an NFL team, Castro may wind up having a successful career. Why? Because the 5’11-205-pound safety out of Iowa, who signed as an undrafted free agent with the Steelers immediately after the draft, is a flat-out football player. Teams bypassed Castro because his 4.6 time in the 40-yard dash is considered slow for a safety, and he possesses neither the burst nor length that could compensate for an absence of straight speed. What Castro lacks in measureables, though, he makes up for in heart, awareness, and determination. Those traits could propel him to a spot on Pittsburgh’s roster come September.

Castro was a three-year starter at Iowa and an All-Big 10 selection as a senior. He had four interceptions the past two seasons, but really made his mark as a tackler and an underneath defender. Castro understands coverages, anticipates routes, and passes them off easily. He knows how to position himself to take away passing lanes. He gets off of blocks easily, closes well to the football, and is a sound tackler in space.

Castro’s lack of high-end speed probably rules him out as a deep safety, but he is an excellent candidate to play in the slot. Pittsburgh is not very deep at that position, with last year’s undrafted rookie, Beanie Bishop, and veteran Brandin Echols the leading candidates to man the role. Echols is currently listed as the starter on the team’s depth chart. But Castro’s ability to play the run, defend bigger receivers, blitz, and play zone will make him a worthy challenger.

The Steelers are deep at safety in other roles, with Minkah Fitzpatrick, DeShon Elliott, Juan Thornhill, and special teams ace Miles Killebrew all expected to make the roster. That could create a battle between two undrafted free agents — Bishop and Castro — for the team’s final safety spot. Bishop has the edge on Castro in terms of athleticism and experience, but Castro is the more physical and technically-sound player. It should make for a compelling training camp battle.

For my film room breakdown of Castro, click the link below:

Sebastian Castro film room.

Castro went undrafted because he lacks elite athleticism. But he makes up for it by being smart, instinctive, tough, and fundamentally dominant. Reminds me of a safety version of Xavier Restrepo.

Do not be surprised if he makes PIT’s roster as their… pic.twitter.com/z9aTXHrHGx

— Kevin Smith (@KTSmithFFSN) May 4, 2025

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