AFL.com.au's chief football correspondent, Damian Barrett, says he "cannot reconcile" Sydney's decision to elevate Callum Mills to the club's captaincy given the midfielder's self-inflicted shoulder injury that will see him miss the first half the season.

Mills, who had shared the captaincy with Luke Parker and Dane Rampe for the past two seasons, was announced as sole captain on Tuesday for the 2024 campaign, four months after the Swans said they were "extremely disappointed" in the 26-year-old for a Mad Monday wrestling incident that lead to him requiring surgery.

The injury means Mills will miss up to 12 weeks of the new season, with the Swans expected to rotate the captaincy among their leadership group until he's ready to return.

Speaking on the AFL Daily podcast on Wednesday, Barrett expressed surprise at the decision given it came so soon after the Mad Monday incident.

"I was (surprised) and that surprise goes back to the act itself, which I still don't think he's properly explained, nor has the club," Barrett said.

"How one of their very best players and the man they have now identified as the standout leader of the footy club can get himself in a situation with effectively a rookie-listed player, a wrestling situation, to the point where his own shoulder pops and he's going to miss at least half the season. I cannot reconcile all of those thoughts and then have him as the standalone captain for the year.

"That's the Swans decision to make though, not mine. That's just my opinion from the outside looking in.

"It was a surprising need to announce it the way they did yesterday as well, given he's not going to be playing football for some time."

AFL Daily co-host Nathan Schmook backed the Swans' call, however, saying Mills will learn from the incident and the experience could even enhance his leadership skills.

"I think sometimes people grow from these things and the upfront conversations he would have had with (coach) John Longmire after the incident. They might have grown closer, which can often happen," Schmook said.

"He would have learnt a lot that he can share with young players about how to behave as an AFL footballer. It's the fact he's not going to be playing for half of the season that I find interesting and how they're going to handle that."

Mills conceded on Tuesday that the incident left him fearing he could be stripped of his leadership role entirely.

"It runs through your mind when you make mistakes," Mills said.

"But I go back to the conversations I had with 'Horse' (Longmire), and the support I felt from the club, board down, was something that was quite reassuring.

"I think the fact is I'm human and I made a mistake but I'm not going to let it define me and be able to lead the group the best I can."

Longmire backed Mills, saying: "His ability to be able to keep thinking of the team and how can we keep improving, is the thing that stands out.

"In the end, that's the thing that still stands out. We all make mistakes, we all learn.

"The ability for Callum to be able to go on this journey, we think is going to be ultimately in his captaincy a real learning experience.

"We've got absolute confidence that he already has been and will continue to be a fantastic leader for this footy club."