Paul Borrington has left Derbyshire after the club opted against offering the batsman a new contract.
The 26-year-old has made seven first-class appearances for Derbyshire this season, scoring 281 runs in 13 innings.
He chose to leave the club with immediate effect to look for opportunities elsewhere.
Derbyshire have also offered left-arm seamer Greg Cork, the son of former England player Dominic Cork, a two-year professional contract.
Cork, a graduate of the Cricket Derbyshire Academy, has been a regular in Derbyshire's second XI.
He also made six appearances for the county in the T20 Blast, taking five wickets at an average of 33.60.
"We've thrown him in at the deep end and his performances have been improving with each game," performance director Graeme Welch told the club website.
"If he continues to work hard at his game, listens and continues learning his trade, there's potential there for a really bright future."