Bush was scheduled to earn a $2.8 million base salary and $50,000 workout bonus in 2014 and count $3.85 million against the Bears' salary cap. Bush will carry $2 million of dead cap money, the remaining prorated amount of the $4 million bonus he received when he signed a four-year, $14 million contract with the Bears in 2012 that included $7 million in guarantees.
Bush carried the ball a career-low 63 times for 197 yards (3.1 yards per rush) and caught the ball just four times for 48 yards last season, despite eating up $3.55 million worth of cap space. The seven-year veteran gained 411 yards on 114 attempts and scored five touchdowns for the Bears in 2012.
Coach Marc Trestman addressed Bush's diminished role in the team's offense at last month's NFL combine.
"I think, No. 1, it was very difficult to take Matt [Forte] off the field, and it was very impressive that he had the endurance to do what he did this year," Trestman said. "There were times that we just felt we had a plan to play Michael more, the defense may have been on the field, and Matt had a good enough rest so we kept Matt out there and didn't get Michael on as much as we would've liked to. We had a plan but we didn't execute it. A lot of that, going in, was Matt's productivity.
"I've experienced this in Oakland when we had Tyrone Wheatley and Charlie Garner. There's a place, certainly, for that type of back. If you have a system of football that's flexible enough, you can seamlessly make that transition and still be just as effective."
Bush ran the ball a career-high 256 times for 977 yards and seven touchdowns for the Raiders in 2011. Second-year running back Michael Ford is an option to assume Bush's role on the roster, although the 5-foot-10 Ford did not have a carry in 2013. Ford returned five kickoffs for 37 yards and made five tackles on special teams.
The Bears could also decide to add another veteran tailback in free agency or address the position in May's draft.
Also Monday, the team released veteran tight end Dante Rosario, who had re-signed with the Bears on a one-year deal Feb. 27.