The Cobblers will not offer centre-back Mathias Doumbe a new contract at the club.
The French 34-year-old was a mainstay of the side last season and scored three goals, the final one in the 3-1 win over Oxford on the last day of the campaign, in 34 appearances.
Manager Chris Wilder is wary of using too much of his budget on defensive players and with Zander Diamond having agreed a three-year deal a fortnight ago, Doumbe will not receive an offer.
“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,” said Wilder.
“We also have players who can play there and elsewhere like Ben Tozer who is 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.
“He 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.”