Alot of people are forgetting his impact during the Van Gaal era. At his best, he has good through balls and offers alot of energy, that is needed to help Pogba since Mata and Henrikh have no pace or urgency whatsoever. Fellaini clearly will not sign a new contract, Herrera is very commited to Manchester United it appears (From what I could deduct from his interviews)
I think some fans overestimated his potential, thought he was going to turn into some sort of world beater after his first season and now are coming to the height of their deception. Give this guy a break, it's one bad season, he's done well in the last three and is still below 30, give him one more year to turn things around and if by early 2019 he hasn't got it together then sell him.