The Bears on Tuesday announced that they have parted ways with offensive coordinator Mark Helfrich, offensive line coach Harry Hiestand, tight ends coach Kevin Gilbride and special-teams assistant Brock Olivo.

The offense struggled throughout the 2019 season, which ended with the Bears finishing out of the playoffs with an 8-8 record. The unit failed to score a first-half touchdown in 11 of 16 games and ranked 29th in the NFL in scoring, 29th in total yards, 27th in rushing yards, 25th in passing yards, 31st in yards per play and 32nd in yards per pass attempt.

All four assistants were part of coach Matt Nagy's original staff in 2018.

Helfrich joined the Bears after directing an explosive offense at Oregon, first as offensive coordinator and quarterbacks coach under Chip Kelly from 2009-12 and then as head coach from 2013-16.

Hiestand was in his second stint with the Bears, having served in the same position for five seasons under coach Lovie Smith from 2005-09. Hiestand rejoined the Bears after spending the previous six seasons as offensive line coach at Notre Dame.

Gilbride was hired by the Bears after spending the previous eight seasons with the Giants, including the final four as tight ends coach.

Olivo served as special teams coordinator with the Broncos in 2017 after working alongside Nagy with the Chiefs from 2014-16 as assistant special-teams coach.