Midfielder Anthony Howell is set to leave Mansfield Town, with the League Two side confirming that contract talks with the player have broken down.
The 28-year-old played 37 matches for the Stags last term, having helped them return to the Football League as 2012-13 Conference Premier champions.
Howell initially moved to Field Mill from Alfreton Town in 2011.
"Talks have stalled and I've told his representative that we're moving on," Cox told the club website.
"I'd never close the door on anyone permanently but with what his agent was asking for with bits and bobs, it was too far off what we can pay."
Howell's likely departure comes after winger Lindon Meikle turned down the offer of a new deal to join York City.