Sweet teammate off the field, a different beast on it, Sebastian Joseph-Days is ready to unleash his fierce persona for the Pittsburgh Steelers.
Over his eight-year NFL career, Sebastian Joseph-Day has stood out as a good teammate and an affable presence.
That reputation should carry over now that the Pittsburgh Steelers have signed the 30-year-old defensive tackle to a two-year, $11-million contract. Still, once Joseph-Day steps on the field, his demeanor changes.
"There is something on the field,” Joseph-Day said. “I don't even think about it. It just happens. I just know what time it is and get locked in. It's time. I am not nice Sebastian, anymore. It's time to get it done. "I'm just 'Bash' then. I don't know."
The Steelers’ reputation for physical play aligns with the side of Joseph-Day’s personality, and it was one of the selling points that brought him to Pittsburgh. Another factor is that Joseph-Day’s hometown, Stroudsburg, Pa., is four hours away.
"It's just the rich history and tradition here," Joseph-Day said. “They represent everything that I feel like I believe in, what football is all about. It's toughness, winning tradition, and I'm only four hours away from my home. I've never been this close to my family. So, being raised in Stroudsburg definitely made it even more enticing.”
Cameron Heyward is the primary defensive tackle in the Steelers’ 3-4 scheme and is a four-time All-Pro. However, Joseph-Day should still get a significant number of snaps backing up Heyward as well as lining up as a defensive end and nose tackle.
"I see myself fitting in anywhere I can," Joseph-Day said. "I'm just here to help make this defense better in any way that the coaches see fit. I'm excited to be part of this group, and I'll do my best, whatever they ask me to do."
Joseph-Day spent the past two seasons with the Tennessee Titans. In 2025, he started 10 of 17 games and recorded 41 tackles, 22 solo stops, six tackles for loss, and two sacks.
Pro Football Focus graded Joseph-Day at 66.6, which ranked 41st among the 127 NFL defensive interior linemen who played enough snaps to qualify.
The Los Angeles Rams drafted Joseph-Day in the sixth round of the 2018 NFL Draft from Rutgers. He played for the Rams from 2018-21, winning a Super Bowl in his final season. Joseph-Day played with the Los Angeles Chargers in 2022 and 2023, joined the San Francisco 49ers in 2023, and played for the Titans in 2024 and 2025.
Joseph-Day has 314 career tackles, 169 solo stops, 30 tackles for loss, 15 ½ sacks, six pass deflections, two forced fumbles, and one interception.
"I just want to show toughness, dependability, and leadership," Joseph-Day said. "Just doing what I have to do to get the job done."
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