I'd have thought if I was in his shoes - having not performed to a consistent standard for several years*, including being unable to be good enough to command a spot on the bench at times, plus making no apparent effort to seek first team football on loan or for a fee (or mutually cancelling contract) - that I'd probably have used all that spare time to ask the manager and the club about my future rather than sit on his hands and then complain about it months later. Communication is two way - it's hard to have huge sympathy here.
*mostly not his fault, but had obviously clear spells where he looked extremely demotivated and played for himself when he came on - pot shots and dribbling down blind alleys instead of playing for the team
Imagine that for Klopp (or generally, for any managers) that you don't want to rock the boat by bringing up a negative to these diva players - in this case 'you know how you haven't asked for a contract and we haven't offered you one? well that means your contract end date will be your end date' - and instead just assume they are doing what they want (quietly seeing out their contract) without any awkward confrontation