Lance Klusener won't be offered a new contract by Northamptonshire after the club said they want to increase the number of England qualified players on the staff.
Klusener, 37, joined as a Kolpak signing in 2006 and has been a consistent performer, especially with the bat. This season he has scored 1095 runs at 73, after his first-innings duck against Essex, including a career-best 202 not out.
"Lance has had another excellent Championship season and no one can doubt his determination and application for the team," chief executive, Mark Tagg, said. "The club, however, has to look forward to the future. With the game going through significant changes over the next couple of years it is important that Northamptonshire are positioned to play a full role both developing talent for the county and hopefully full international duty.
"We have consistently stated our desire to increase the number of England qualified players beyond this season and especially provide real opportunity for the talent that the academy is producing".
Offspinner Jason Brown has also been released after 12 years with the club. His success in Championship cricket has diminished since his best return of 66 wickets at 23.71 in 2006. This season he has taken just nine wickets in nine Championship matches.
After a haul of 61 wickets in the 2000 season he was named in the England squad to tour Sri Lanka in 2000-01, but couldn't force his way past Ashley Giles and Robert Croft into the starting XI. It was the closest he came to international recognition.
"This was a difficult decision for the club to make given Jason's commitment and dedication to the club over many years," Tagg said. "However, it was felt that this was the right time for both parties and gives Jason an opportunity of potentially continuing his career elsewhere while enabling younger players to develop at Northamptonshire."