Bosio served as the Cubs pitching coach from 2012-17, where his work with the club's staff was synonymous with the team's elevated presence on the mound.
Things changed late this year, though, as pitching was a weakness for the Cubs during the 2017 playoffs. In the NLCS against the Los Angeles Dodgers, Cubs pitchers posted a collective 5.36 ERA.
There are a few well-regarded pitching coaches currently looking for work who might be seen as replacements. Mike Maddux, who spent the last two years as the Washington Nationals pitching coach, is now available after the Nationals let manager Dusty Baker and all of his coaches go on Friday.
Also searching for a new job is Jim Hickey, who spent the last 11 years in the position with the Tampa Bay Rays before leaving the organization earlier this month. Hickey was first brought to Tampa Bay by former Rays skipper Joe Maddon, who now manages the Cubs.
Chicago is reportedly already interested in bringing Hickey aboard as Bosio's replacement, sources told Robert Murray of FanRag Sports.
Before he moved into coaching, the 54-year-old Bosio pitched in the majors for 11 seasons, throwing a no-hitter with the Seattle Mariners in 1993.