For some perspective on Day, you should check out the Elliotte Fridman's
profile on him
Lots of interesting info like
In conversations both on and off the record, it’s clear people who do know Day really like him. He laughingly calls himself “a goofball.”
While his fun-loving approached worked on a personal level, it didn’t always help him on the job. By his own admission, when he was younger, Day relied on his prodigious talent, and, at that time of his life, did not put in the work. In researching this story, I learned that his combine performance for the 2016 draft is still discussed by people who were there. Day showed up “with a total bedhead,” according to one source, and did very poorly in testing.
per his junior coach Rocky Thompson, from the same article
“Sean was a horse for us. When we won the Memorial Cup, he was basically playing every other shift. His defensive game got so much better. Erie (beaten by Windsor in the Memorial Cup Final) was basically an all-star team and he was out there against NHL-level players. He was a big reason we won.”
per Day, himself, same interview
“Whenever somebody says, ‘Do you want it?’ Well, I had hip surgery and I came back a month early, just to prove to everybody that I want this.”
There's also a section about Day's brother who killed a woman, driving drunk, and was sent to jail.
It's a very interesting read and gets you a little perspective on Day, aside from the usual "Haha exceptional player gone bust" talk that usually surrounds him. You can definitely read parts that you know would tick a team off (the goofball comment could be read as code for off-the-ice behaviour; and there's also part that calls into question his defensive side of the game) but you can also read some parts that lead you to believe there might be something there and it just became a case of a team giving up on a guy because he was drafted under the previous guy's watch (the section on his hip surgery is quite illuminating along with Day hiring someone to test him for food allergies in order to get in better shape can lead you to believe that there maybe is more drive than previously suggested and the fact that no one really has anything bad to say about him/that he's a well-liked teammate).
For a team like Tampa, who doesn't exactly have a well-stocked cupboard of prospects, I think he's a good home-run swing. Give him a year to see if the talk has merit, and cut ties then, if need be.