Reliable seamer Tim Groenewald has chosen to leave Derbyshire at the end of the campaign, ending six seasons with the county he joined from Warwickshire.
The 30-year-old, born in South Africa but a non-overseas player due to his English mother, has been a regular for Derbyshire.
He helped them gain LV= County Championship promotion for the first time in 2012, although they could not stay in the top flight last year.
Groenewald, also a handy lower-order batsman, has played 72 first-class games for Derbyshire and taken 229 wickets, at an average of 29, including a hat-trick versus Essex in April.
He has also claimed 103 limited-overs wickets for the Falcons and was capped by the club in 2011.
Elite performance Director Graeme Welch said: "Tim has been a terrific player for Derbyshire and we respect his decision to move on.
"We are absolutely committed to our long-term vision for success and we have an exciting crop of young seam bowling talent coming through with the likes of Ben Cotton, Tom Taylor, Matt Higginbottom and Greg Cork.
"Tim's decision creates a terrific opportunity for these lads and we will continue to build for the future by providing these young lads with first team experience, which can only be good for them and the future of Derbyshire cricket."