According to media reports, Steelers defensive assistant Joey Porter saw Blount leaving early and called him back into the locker room several times. Blount finally went back in briefly but left again even before his teammates had begun postgame interviews.
Blount, who signed a two-year, $3.85 million contract with the Steelers in March, played only a couple of snaps against the Titans.
He did not receive a carry in a game for the first time this season as the Steelers leaned heavily on Le'Veon Bell, who rushed for a career-high 204 yards and a touchdown on 33 carries.
Bell had all but three of the Steelers' carries on a night in which they improved to 7-4. Quarterback Ben Roethlisberger had the other three carries for 4 yards.
Bell had rushed for 205 yards and no touchdowns on 57 carries over the Steelers' previous four games entering Monday night. He nearly matched that rushing output while setting a career high in carries against the Titans.
Blount is second on the Steelers with 266 rushing yards but has not played as big a role in the offense as he envisioned in large part because Bell has emerged as one of the most dynamic running backs in the NFL. Since running for 121 yards against Carolina on Sept. 21, Blount has only 48 carries in eight games and hasn't had more than 29 yards in a game.
Blount is with his fourth team in five NFL seasons. He missed most of his senior season at Oregon after getting thrown off the team for punching an opposing player.
Blount and Bell were arrested in August for misdemeanor marijuana possession after they were pulled over on the way to Pittsburgh International Airport for a team flight to Philadelphia for a preseason game.
Bell also was charged with driving under the influence, and coach Mike Tomlin said the two would be punished internally. The eighth-year coach never disclosed how he punished the two running backs, and neither Bell nor Blount missed any playing time.
Blount's leaving the field early could lead to discipline from Tomlin. If the Steelers consider releasing Blount, they will have to weigh that against the reality that they are already thin at running back.
Rookie Dri Archer is the only other running back on the roster, and he has played sparingly, rushing for 41 yards on eight carries.
Information from ESPN Stats & Information and The Associated Press is included in this report.