Former Cobblers trio Andy Williams, Dai Cornell and Vadaine Oliver have all been released by their respective clubs.
Williams departs Cheltenham Town after 13 goals and two years at the club while goalkeeper Cornell leaves Peterborough United following their relegation to League One.
The 31-year-old had four years at Sixfields before a brief spell at Ipswich was followed by a switch to rivals Posh in the summer of 2021. He departs the club alongside Serhat Tasdemir and Kyle Barker.
Meanwhile, Oliver has been linked with a move up north after leaving Gillingham. The striker turned down a new contract at Sixfields in 2020 and enjoyed two successful seasons with Gills.
However, he was unable to keep the club in the third tier this season despite scoring 10 league goals.
Also leaving Gills are Ryan Jackson, Harvey Lintott, Christian Maghoma, Mustapha Carayol, Danny Lloyd, Gerald Sithole, Ben Thompson and Aaron Chapman.
Elsewhere, Joe Powell has been offered a new contact by Jimmy Floyd Hasselbaink at Burton.