"I was struggling to get through the 90 minutes, the twisting and turning was a real problem and I wasn't doing myself justice. I knew that it wasn't fair on the Club, the manager and myself so I've made a decision to call it a day.
"Jim has been fantastic to me and I owe him so much and honesty is one thing that I can give him in return."
Nash says that he would now like to go into coaching: "It's a sad time but life goes on and there are far worse things in life. Rather than look back, I want to push on and coaching is a challenge that I would like to take up.
"I've spoken to Bryan Klug and there maybe something that can be sorted out for me here in terms of learning the coaching trade.
"You can't beat playing but coaching is the next best thing and it's a path that I would like to follow.
Nash made one apperance for the blues, coming on as a sub in the 6-1 win over Burnley in the Championship towards the start of the 2003/4 season.