Northamptonshire have offered 35-year-old batsman David Sales a new one-year deal but have announced the release of four players.
Sales has been with the county his entire career, making his first-class debut as an 18-year-old in 1996, and scored 919 runs as Northants gained promotion from LV= County Championship Division Two this season.
But 32-year-old left-arm spinner Con De Lange, former Durham seamer Luke Evans and young duo Sam Sweeney and Christian Davis have been let go.
"Releasing players is always a tough decision. But players do get to an age when they need to be playing regular 1st XI cricket," said chief executive David Smith.
"We believe that Con, Sam, Christian and Luke are at this stage of their careers and had yet to claim regular first-team places.
"Northants Cricket would like to thank the players for all their effort and time and wishes them well in the future. They will always be welcome at Northants."
Northamptonshire have also started the process of recruiting a new left-arm spinner, a seamer and an overseas bowler.
A club statement read: "The players have been identified and head coach David Ripley is currently talking to those players. The club hopes to make an announcement shortly."