Mathias Kouo-Doumbe will leave Northampton this summer after the club confirmed he will not be offered a new contract.
The 34-year-old French defender made 34 appearances since arriving at Sixfields in September 2013 but boss Chris Wilder says his side have enough defensive options.
"Mathias has been unfortunate but with Zander Diamond signing and Kelvin Langmead and Lee Collins coming back to fitness we are well covered in the central defensive position," he told the club's official website.
"We also have Ben Tozer already under contract and we have had encouraging talks with Gregor Robertson and it is important to get the balance of the squad right. We can't over stock in one position at the expense of elsewhere.
"Mathias is an excellent professional who played a big part in our good run in the second half of the season and I am sure he will get fixed up and do very well for another club.
"Mathias has been really unfortunate not to get a contract here but we thank him for his efforts here and wish him every success for the future."