2) Griffin Canning
In terms of overall ability, Griffin Canning is not the second-best player on this list. In fact, he'd rank towards the bottom overall. The reason he's so high on this list is because he's a controllable starting pitcher. Those are incredibly valuable.
The Angels starting pitching is nowhere near good enough. That's not a secret. Trading Griffin Canning would make it even more of a problem. Parting with him would sting, but there are a couple of reasons why the Angels might want to do it right now.
Canning set career highs with 24 appearances, 22 starts, and 127 innings of work. This was his only MLB season with 20+ starts and 100+ innings pitched. Canning's always been an injury risk, getting something for him after his healthiest season could make some sense.
Another reason the Angels might consider trading Canning is because of what they might be able to get in return. The Angels had to give up a ton just to get Lucas Giolito, a pitcher with somewhat similar numbers in recent years with just a couple months of control. Canning has two full years of team control. He might bring the Angels back more than they gave up for Giolito.
Again, it'd be hard to see Canning go, but if the Angels plan on rebuilding or just testing his value in general they might be happy with what they get in return.