He's a role-model professional taking care of his body extremely well and we can afford it, so two years at the same terms as he's had would be very fair after this season. Even if he's role would diminish in 2021, he'd still be a very good player to have in the dressing room and to bring on as an impact player at the end of the game given the man can run a marathon below three hours with ease and is playing such a key role in those situations late in games.
Thats my hope, that he's treated his body so well, that he'll be able to extend his playing days far beyond his peers.
Can't help but recalling Javier Zanetti who was able to continue playing for Inter well into his late thirties, thanks to how well he treated his body. Zanetti famously, on his wedding day, brought along a pair of trainers, to nip off for a quick run between the ceremony and the reception, you know like you do? On his honeymoon, his wife "accidentally" booked a hotel without a gym, so he did squats with his wife on his back, on the beach of course, it was their honeymoon after all.
Milner seems like he is cut from the same cloth, and although the intensity of a Klopp team may not allow him to continue playing regularly until he's nearly 40, I'm hoping he'll stick around for a few more years at least, and I agree with other posters that he should be given a coaching role. Considering how Klopp has underlined the importance of Milner's communication abilities, I'd imagine that Klopp has already discussed that possibility with him already.