Roquan Smith, LB
This one's a little bit of a stretch, admittedly, because the Bears didn't quite give up on Smith. The linebacker, who was drafted 8th overall in 2018, requested a trade during training camp of 2022 after the two sides couldn't come to an agreement on an extension. He returned to camp without a new deal in place, but was traded to Baltimore a few months later.
After making two Second Team All Pros with the Bears, Smith ended his first season with the Ravens by making his first First Team All Pro. He ran it back again in 2023, again making the First Team All Pro, and finishing 8th in Defensive Player of the Year voting. He was an elite linebacker with the Bears, and has since become one of, if not the, best off ball linebackers in football since finding his footing in Baltimore. The Bears moved on to TJ Edwards and Tremaine Edmunds, who have been good for them (especially Edwards), but the opportunity to keep Smith in Chicago for his whole career, as the next truly great Bears linebacker, was missed. Fortunately for Bears fans, NFL players don't go into the Hall of Fame associated with any one team.