Sebastian Joseph Day is leaving the Tennessee Titans for Pittsburgh, where he is expected to fill a rotational role behind Cameron Heyward and Derrick Harmon on the Steelers’ defensive line.
The Pittsburgh Steelers have agreed to terms with free agent defensive lineman Sebastian Joseph Day on a two-year, $11 million contract that includes $6 million guaranteed in the first year, according to ESPN’s Adam Schefter. The deal was finalized Friday and was confirmed by Joseph Day’s agent, Drew Rosenhaus.
Joseph Day, who turns 31 next week, arrives in Pittsburgh after two productive seasons with the Tennessee Titans and brings a career built on versatility, durability and a Super Bowl ring earned with the Los Angeles Rams.
What Joseph Day brings to Pittsburgh
Over his two seasons in Nashville, Joseph Day appeared in all 34 possible regular season games, logging 22 starts and establishing himself as one of the more reliable contributors on a Titans defense anchored by star defensive tackle Jeffery Simmons. He was used across multiple alignments, playing meaningful snaps at defensive tackle, defensive end and edge defender during the 2025 season alone, a versatility that ranked him among the fourth-highest graded regular starters on the Tennessee defense in both of his seasons there.
His two-year totals with the Titans include 85 tackles, 4.5 sacks, nine tackles for loss and one pass breakup. In 2025 specifically, he finished with 41 tackles, two sacks, six quarterback hits and a fumble recovery across 17 games, contributing steadily even as his role shifted depending on the game plan and personnel groupings around him.
Across his full NFL career spanning eight seasons, Joseph Day has accumulated 314 tackles, 5.5 sacks, one interception, six pass breakups and two forced fumbles, numbers that reflect a player who has never been a headline pass rusher but has consistently held up as a dependable interior presence.
A career that has taken him across the league
Joseph Day’s path to Pittsburgh has wound through several NFL franchises. The Rams selected him in the sixth round of the 2018 draft, and he remained in Los Angeles long enough to be part of the franchise’s Super Bowl LVI championship team, one of the more meaningful achievements of his career. He subsequently spent time with the Los Angeles Chargers and the San Francisco 49ers before arriving in Tennessee ahead of the 2024 season.
That cross conference experience gives Joseph Day a perspective on different defensive systems and coaching philosophies that can be valuable for a veteran in a rotational role, where adaptability and scheme familiarity matter as much as raw talent.
His expected role with the Steelers
In Pittsburgh, Joseph Day is expected to operate as a rotational defensive lineman behind starters Cameron Heyward and Derrick Harmon. At this stage of his career, a depth and rotation role suits what he brings to the table. He is not expected to be a primary pass rusher or featured run stopper, but a reliable veteran who can play multiple spots along the line and give the Steelers quality snaps in a reserve capacity.
For a Pittsburgh defense that values interior depth and scheme flexibility, adding a player who has lined up at defensive tackle, defensive end and edge defender within a single season provides coordinator options that purely positional players cannot. Joseph Day’s familiarity with playing alongside dominant interior defenders, having done so alongside Simmons in Tennessee, also suggests he understands how to function effectively in a complementary role without needing to be the focal point of a defense.
The Steelers continue to build out their roster ahead of the 2026 NFL Draft, and Joseph Day’s signing represents another piece added to a Pittsburgh defense working to remain competitive in what figures to be another challenging AFC season.