When the 2017 NFL draft dust settled and the first thoughts in the scouting community turned to 2018, the name Arden Key was right up there near the top of the list.

Key had dominated on an LSU defense that was among the best in the country in 2016. The sophomore pass rusher turned in 55 tackles, 11 sacks and two forced fumbles (in only 11 games), flashing some freaky pass-rush ability and possessing a condor-like wingspan in his 6-foot-5 frame.

It appeared all but certain he was headed for the top 10 picks of the 2018 NFL draft.

An unexpected thing happened along the way — several things, in fact. Key immediately drew raised eyebrows when he left the program last winter to take care of some personal matters, the details of which have been shrouded. When Key eventually returned to the team in early June, it was discovered that he recently had surgery to repair a rotator cuff injury that he played the previous season through.

As if the questions about Key weren’t piling up already, he returned to the team at a whopping 278 pounds at his heaviest. For context, Key recently weighed in at the NFL scouting combine at 238 pounds and reportedly played in the 240-pound range during the 2016 season.

But Key did not work out at the combine, choosing to wait for his pro day on Wednesday this week. Instead, he spent the majority of the time explaining to NFL teams what happened last year. Key said he felt good about the process and that teams responded favorably to his answer for why he left the program briefly.

“They respond in a good way,” Key said last month in Indianapolis. “I surprise a lot of them, because a lot of them don’t know what happened. I tell them what happened, what I played a part in, but yeah, a lot of them are surprised. They’re blown away by the interview.”

We reached out to two NFL teams that spoke with Key to find out what happened — and we double-checked with a source in Baton Rouge. Key left the program to enter rehab, they said, for marijuana. The feeling we got was that the NFL wasn’t too concerned about that, even though he was briefly suspended after one failed test upon returning to school.

The biggest concern, we hear, is that Key — who was not in regular contact with the school for a period of time during his absence — started listening to people outside the program for advice on how he should progress in football. Against the advice of LSU’s team doctors, Key was compelled to have his shoulder operated on. The school’s medical staff had looked at Key’s shoulder, which bothered him for some time, and determined that surgery was not necessary.

Key said at the combine that the shoulder “doesn’t give me any problems now” and that he’s good to go. But the timing of it resulted in him missing the early part of the season — and the school was caught off guard by the whole thing at first.

An NFC scouting director said that raises a red flag.

“It’s always concerning when you have [players] going out on their own for medical advice, second opinions, because you don’t always know what people are telling them,” the director said. “You’re going to listen to some other doctor that’s never seen you before because a mentor of yours recommended him? That’s where we have concerns. It’s not the weed or the weight or any of that; that stuff we can deal with.

“The problem is listening to some coach you’ve known forever or some family member getting in their ear and telling them that the [school] doesn’t have their best interests. Look up at New England, that whole mess with Tom Brady and the doctors and that trainer [Alex Guerrero] recruiting guys away from the [Patriots medical staff] … teams worry about that. They want to know everything that’s done to their players.”

The LSU source confirmed the timeline and concern about outside influences. The source also added that Key was “completely, madly, wildly out of shape” upon returning — he first played against Mississippi State — but worked his way into form by the Florida game. LSU lost to Alabama later in the season but Key “played his ass off” in the game, the team source said.

Key has terrific talent, and yet his substance history, weight and poor play certainly don’t make him a squeaky clean evaluation. Add that to the fact that a 238-pound Key reportedly ran a 4.85-second 40-yard dash Wednesday after skipping the event at the combine. “I know how much technique is involved in the 40, so I said, nah, I’m just going to wait until Pro Day,” Key told the media in Indy five weeks ago.

Key had been training for the pro day with private pass-rush coach (and former Atlanta Falcon) Chuck Smith, whom he’s known since high school.

The LSU source likes Key and said people in the program are rooting for him to be successful — but that he has some maturing he needs to do and that earning the trust of his NFL team will be crucial over the coming weeks.

“It’s weird to say it this way, but Arden is a sweetheart,” the source said. “Arden gets his ass into trouble because he’s a people pleaser. … He’s got to learn to listen to the people he works for [in the NFL]. If he keeps listening to the outside voices, it’s going to be an issue for him. That’s the issue. He’s got to figure out what it is to be a grownup.”

The AFC team we spoke with said they did not knock Key off their board for off-field concerns but have affected their draft grade on him.

“We tend to think about players who have as much going on as he does in [Round 4]. Talent-wise, should he go much higher? Yeah. But you just can’t commit to a player you don’t trust.”

Told about the sweetheart comment from a member of the staff, the AFC scout said: “I believe that. And I’ll sign off on a sweetheart [who has] gotten in trouble if I think he’ll listen to us. That’s where the concern is.”

Key said at the combine that he’s “coachable, a people’s person, a loving caring guy” and that he’s “got a good smile.” He echoed his sentiments of last month on Wednesday to the media that he believes scouts are coming away with a better impression of him once he shares the details of his absence.

“A lot of scouts viewed me differently before meeting me,” Key said. “And when they met me, I told them the truth — the full, honest truth — and took responsibility of those things. Now they look at me in a different eye.”

But have the concerns over the decision to have the surgery and the outside influences been assuaged? That’s likely the biggest question that will determine where this one-time top-10 talent will end end in the 2018 NFL draft. It's almost certain he won't be a first-round pick, but how far will he fall?

“Do you and I know that the Bengals are going to take Arden in the third round because they don’t care about any of that stuff? Yeah.” the team source asked (and answered) rhetorically. “And he’s going to end up having a monster rookie year and then you fear he'll start to dip … just like Jeremy [Hill] did.

“If I had a million dollars, I would just bet that the Bengals draft him. He just has that feel about him.”