Cross yet another need off the Steelers' wish list.
According to multiple reports, the Steelers have signed underrated nose tackle Sebastian Joseph-Day to a two-year contract for $11 million.
The immediate thinking is that Joseph-Day, a 6-4, 310-pounder, was added to provide depth behind Keeanu Benton, but Joseph-Day has started 90 of the 105 games in which he's played over the last seven seasons. He's a run-stuffer who joins a team trying to return to its days of stopping the run first in what's become a run-first division.
Here are some of Joseph-Day's analytics provided by Mike DeFabo of The Athletic:
Sebastian Joseph Day was the 9th best iDL in free agency in @danielrpopper’s rankings. Here’s his full report: pic.twitter.com/QGXf6PEoLa
— Mike DeFabo (@MikeDeFabo) March 13, 2026
A better definition of Joseph-Day's under-the-radar skills was laid out by Brandon Staley upon meeting Joseph-Day when Staley became defensive coordinator of the Los Angeles Rams in Joseph-Day's third season with the team:
"I introduced myself," Joseph-Day said of Staley, "and he goes, 'I know who you are.' I was like, 'You do?' He was like, 'Yeah, I know who you are. You're a good player. People don't know about you yet, but people are going to find out about you real quick. You're an up-and-coming, great defensive lineman that people are going to find out about.'"
Joseph-Day, at the time, was coming off his first season as the starting nose tackle for the Rams. They had drafted Joseph-Day out of Rutgers in the sixth round of the 2018 draft. He became the starring nose tackle in 2019 and made 38 consecutive starts before tearing a pectoral muscle in the middle of the 2021 season. He returned in time to play in the Super Bowl that season, which was won by the Rams.
Staley had moved on to the Chargers, and after Joseph-Day's contract expired following the Super Bowl, the Chargers signed him for three years at $24 million. Joseph-Day made a career-high 46 tackles in 2022 and also intercepted Russell Wilson.
But in 2023, Joseph-Day's tenure with the Chargers came to a shocking end. Voted defensive captain by teammates before the season, Joseph-Day started 14 games, but the Chargers fell to 5-9 with an embarrassing 63-21 loss to the Raiders on a Thursday night. Staley and GM Tom Telesco were fired the next day, and Joseph-Day was released a week later. The 63-point yield to the Raiders may have had something to do with the release, but the Chargers were also looking at a $42 million cap deficit the following season.
Joseph-Day rebounded with the 49ers. He played in the final two games and then in another Super Bowl.
Joseph-Day didn't win a ring with the 49ers that year, but did sign with the Tennessee Titans, where he spent the last two seasons. He reached an agreement with the Steelers just after the team had introduced newcomers Jamel Dean, Rico Dowdle, and Michael Pittman Jr. to the Pittsburgh media.
Great signing for Pittsburgh. Sebastian is the epitome of a 3-4 defensive lineman. Omar Khan & Mike McCarthy have quietly won free agency this year. They’ve gotten a bunch of quietly good players. I see 9-10 wins for the Steelers this year if they can resign Aaron Rodgers. https://t.co/BpDrf7hUek
— Breiden Fehoko (@BreidenFehoko) March 13, 2026
Joseph-Day was born in Stroudsburg, a town situated among the Pocono Mountains in northeast Pennsylvania. He led Stroudsburg High to back-to-back Mountain Valley Conference championships before accepting a scholarship offer from Rutgers as the No. 30-ranked prospect out of Pa.
Joseph-Day, who'll turn 31 next Saturday, spent five years at Rutgers and finished with 90 tackles, 14.5 tackles-for-loss and 3 sacks. At his pro day, he measured 6-3, 299, with 34.5-inch arms. He ran a 4.97 40 (1.68 10) and had a 31.5-inch vertical jump. He pushed the bar up 24 times on the bench press.
In his seven seasons, the run-stuffing Joseph-Day also compiled 15.5 sacks and 43 QB hits.
New Steelers NT Sebastian Joseph-Day with his son (Photo: Jayne Kamin-Oncea, USA TODAY Sports)