The 26-year old Republic of Ireland international will not sign a new contract with Coventry after his current one expires at the end of the month and is likely to make the switch to the Premier League this summer.
"Keiren has written to the club confirming that he will not be signing a new deal," said Coventry boss Andy Thorn.
"He has been an outstanding player for this club and I would personally like to wish him all the best for the future.
"The club obviously has no say on where he goes now but he has gone about everything in completely the right way.
"It is nice to have some clarity on the situation and now we can move on with preparations for the new season.
"The chairman and I are working hard to bring in players including someone to fill the goalkeeping position."