Im gonna break my self-imposed ban to comment on this.
This article basically confirms what me and others have been saying for months.
1) Hayward wasn't in game shape yet. "His foot was the one injured, it is healed now, he should be back to all-star by now", "it only took me 3 months to recover from my fracture" just some of the things people shoved in my face when I told them that when you do something at the highest level for a very long time and you suddenly stopped doing it for some time, you will have a lot of trouble getting back into condition.
2) Hayward's mental issues and tentativeness has something to do with his teammates, the team's performance and his own performance. I've said it before, the team is playing bad and he cannot do anything to help, there will be doubts creeping in your mind about how your teammates are feeling and the result is you not wanting to step on someone's shoes.
3) Reps are needed for him to succeed. This is why they started him, they wanted him to feel comfortable and establish chemistry with the starting unit. In hindsight, it might have been too early and it backfired. But right now he has to be given minutes and opportunities. That's why I kinda disagree on sending him back to the starting lineup. What he needs is to be given the absolute keys to the 2nd unit to do what he wants. Rozier and Morris needs to have their shots reduced some more and give them to Hayward.
4) He mentioned about PG saying it was 2 years before he got back to playing normal. A lot of fans wanted to trade him for a bag chips because of how he performed this season, while a lot of rational fans here are saying PG wasnt any good when he came back from injury. Guess who is right.
The Celtics need Hayward to be an All-Star for this current Celtics team to be a contender. If he cannot, a trade is needed for another All-Star. That's the reality. But how is that gonna happen? Minutes, Opportunities, Patience and Time. No, Hayward getting opportunity despite playing poorly isn't because of favoritism or because he is a vet and what not (usual hater narrative btw). It is because the organization is supporting him because they need him.