Jim Magilton has told the Club website that he expects Shane Supple to go out on loan next week with Blues bringing in a replacement.
The Town boss agreed to the Republic of Ireland U21international's request last month to go out on loan so he can get some first-team experience as long as Blues can find some cover with Grimsby now a likely destination for the Dubliner.
"Grimsby are keen to take Shane and we are hoping it can all be confirmed some time next week," Jim told the Club website.
"It's the hardest position in the squad, understudy 'keeper and the lad is desperate to play games so we've been trying to get him out on loan for a few weeks.
"We can't let Shane go though until we have tied up a 'keeper as cover for Richard Wright and I'm confident we will be able to confirm that next week."
Shane's likely loan spell at Grimsby would initially be for a month, with the 'keeper following in the footsteps of fellow Blue, Liam Trotter, who spent three months at Blundell Park earlier in the season.