Bell was informed of the team's decision on Monday ahead of the 4 p.m. ET deadline Tuesday for NFL teams to designate an unrestricted free agent on their roster as a franchise player.
Bell was frustrated by negotiations last year and turned down a reported five-year, $40 million deal in 2017 before playing last season under the franchise marker. But not before he held out for all of training camp and reported days before the regular-season opener.
The Steelers had been hopeful since being eliminated from the 2017 playoffs they would be able to reach an agreement with Bell before the March 6 franchise tag-deadline.
Bell, too, said during Pro Bowl week in January that he was optimistic the two sides were approaching a long-term agreement. But he also suggested that sitting out the season or retiring were options.
Pittsburgh general manager Kevin Colbert told reporters last Wednesday in Indianapolis that the team is "(trying) to figure out common ground" with Bell's representatives at the NFL Scouting Combine.
But NFL Network's Ian Rapoport reported Monday that the Steelers are expected to franchise tag Bell barring a dramatic turn in talks, according to sources informed of the situation.
If the two sides are unable to reach a deal, franchising Bell would cost around $14.5 million for 2018. Bell earned a base salary of $12.12 million last season after the Steelers placed an exclusive tag on him.
The Steelers and Bell have until July 16 to work on a long-term deal. If a deal is not struck by that deadline, he would play under the one-year tender once again.
Bell, 26, will be entering his sixth NFL season in 2018. The two-time first-team All-Pro and three-time Pro Bowler has rushed for 5,336 yards and 35 touchdowns over 62 games. His TD total ranks third on the Steelers' all-time rushing scores list and his yardage total ranks fourth.
Last season, Bell rushed for 1,291 yards and nine TDs in 15 games.
--Field Level Media