This is an interesting one. Alisson turns 30 later in the year which isn't too old for a goalkeeper. While I wouldn't bank on him going until he's 40 odd, if he avoids injuries I'd be surprised not to see him still playing in five or six years, hopefully still with the reds. Kelleher won't want to sit around for that long and nor should he.
He's not actually played many first team games but even so he's became a very good young keeper and has experienced a couple of trophy wins already, and at 23 he could have another fifteen years ahead of him. I think a lot will come down to who wants to take a chance on him whether it be a loan or transfer. This time last year I was thinking let him go on loan to the Championship for experience, now I'm almost certain he could do better, unless there was another Fulham say who you know where going to be promoted, and you could see the player making the drop and keeping his place upon promotion to the PL.
I wonder if a loan could interest him, because he obviously can't take a step up from LFC, but if he went elsewhere and became number 1 at a good level he may be keen to continue that in the future.