The Bears on Tuesday placed linebacker Matt Adams on injured reserve.
The fifth-year pro exited Sunday's loss to the Vikings with a calf injury. Adams has appeared in three of the Bears' first four games, all as a reserve, playing primarily on special teams. He has recorded six tackles on defense and one stop on special teams.
Adams must miss at least four games, meaning that he won't be eligible to play again until Nov. 13 when the Bears host the Lions at Soldier Field.
The Bears signed Adams to a one-year contract April 9.
He spent his first four NFL seasons with the Colts, contributing primarily on special teams. During his four years in Indianapolis, Bears coach Matt Eberflus was Colts defensive coordinator.
Selected by the Colts in the seventh round of the 2018 draft out of Houston, Adams played in 58 games with nine starts for Indianapolis, registering 55 tackles and six tackles-for-loss.
All nine of his career starts came in his first two seasons. Last year he appeared in all 17 games, all as a reserve, playing just one snap on defense.