Cobblers manager Gary Johnson announced his retained list earlier this week, but has since decided that the former Hereford man is free to find a new club.
Johnson said: "I just felt we needed to create space for a few more new faces.
"Dean did well for us and never let us down. I am sure he will be able to find a new club and we wish him well for the future.
"From our point of view, and on reflection, I just felt we would benefit from having one or two more new faces in to help us move on and move forward.
"That is the decision I have made."
Source: PA
Source: PA