According to sources, Glennon will sign for Carlisle United on a free transfer.
He spent the 2000/01 season on loan at Brunton Park from Bolton - winning their 'player of the year' award - before Brian Little brought him to Hull in a £50,000 deal.
After a mixed season last year, Jan Molby made him his number 1. However, his performances have come under scrutiny recently and was dropped for the game at Oxford last week.
This leaves Paul Musselwhite as the only goalkeeper at the club, and Molby will now have to look to loan signings and free transfers until the transfer window re-opens in January.