The 34-year-old broke a leg in two places at the beginning of last season, but returned to make seven substitute appearances this term.
And after being told he can only continue playing if he trains less, he has decided to retire when his current deal runs out at the end of December.
He said: "It is not the sort of decision that can be taken lightly or on the spur of the moment. It is something that I have been thinking about for the last four of five weeks
"I am contracted here until the end of this month and I have told the gaffer that if he needs me I will make myself available.
"It will be sad to leave but all good things come to an end. I would like to thank all the supporters who have been good to me.
"They gave me a great reception when I came back against Yeovil and I will always remember that."