Bowler first arrived at the county in 2015 but is now free to pursue other options ahead of the new season
Derbyshire have parted company with allrounder Tom Milnes by mutual consent.
The seamer, who was in the final year of his contract with the county, came through the academy at Warwickshire before making the move to Derby, initially on loan, in 2015.
He played 17 matches in all formats, taking 22 wickets, but has now been allowed to leave.
The county's cricket advisor Kim Barnett said: "Tom is a true professional. He has always given his all on the field and is well-respected by his team-mates.
"With opportunities likely to be limited for Tom in the coming season, we have agreed that he should be able to pursue his career elsewhere. We wish him all the best for the future."