Pace also announced that the team planned to release linebacker Willie Young. The Bears made that move official later Wednesday.
The moves will be the latest in an offseason purge of veterans by the Bears, who have already released linebackers Jerrell Freeman, Pernell McPhee and safety Quintin Demps. The team also declined the option on offensive lineman Josh Sitton's contract, making him a free agent.
Glennon was scheduled to make $12.5 million as the backup to Mitchell Trubisky in 2018. The Bears are already on the hook for Glennon's fully guaranteed $2.5 million roster bonus, putting the total price tag for Glennon's one-year stint in Chicago at $18.5 million. The Bears, however, will open up $9 million worth of cap space with his release.
Not only was Glennon, 28, making way too much money to back up Trubisky, whose total contract is valued at just more than $29 million guaranteed, but Glennon doesn't seem to fit the up-tempo style of offense that new head coach Matt Nagy is expected to run.
After the season, Pace said he had no issues with signing Glennon after aggressively targeting him in free agency last spring.
"With the quarterback position, I have no regrets in us being aggressive in attacking that position; it's that important," Pace said. "We all felt confident in Mike, and sometimes in our business, things don't work out."
Glennon turned the ball over eight times -- five interceptions and three fumbles -- in four starts before Chicago switched in Week 5 to Trubisky, the second overall pick in the 2017 NFL draft. Glennon did not play the rest of the season.
Glennon started 18 games for the Tampa Bay Buccaneers from 2013 to 2014. He has thrown for 4,933 career yards and has 34 touchdowns and 20 interceptions. He also has seven career fumbles.
An eight-year veteran, Young has been one of Chicago's best pass-rushers since he joined the club in 2014. Young set a career high with 10 sacks in his first year in Chicago, and he signed an extension in the summer of 2016 after he switched from defensive end to outside linebacker to fit in the 3-4 defense used by veteran coordinator Vic Fangio.
Young suffered a triceps injury last year that landed him on injured reserve after Week 4's loss to Green Bay. The 32-year-old was due a roster bonus of $1 million on the third day of the league year -- Young's 2018 base salary was scheduled to be $3.5 million.