ESSENDON did not know about the Jake Carlisle video before he was traded to St Kilda, but the club will remind its players about behavioural standards when they return from their off-season break.

Vision of Carlisle appearing to snort a white substance was aired on television just hours after the Bombers and Saints had lodged a trade which saw the key defender land at Seaford and the Saints give up their prized No.5 pick.

It led to Carlisle admitting in a statement he had made an "error of judgement" and a "very poor decision", and he cut short his overseas holiday to return to Australia and meet with St Kilda's hierarchy.

Questions have been raised about when Carlisle's camp and the Bombers became aware of the existence of the footage, but Essendon general football manager Rob Kerr said the club did not know about it before agreeing to the deal.

"We didn't know. I spoke to Anthony McConville (Carlisle's manager) yesterday to try to piece together when he actually knew," Kerr said on Thursday.

"The thing with Jake's trade was actually supposed to go through the day before, and then Craig Bird was umming and ahhing. It was a big move for him to go from Sydney to Melbourne.

"Craig held that up a bit. We got the word later that night that he was happy to go, so we scheduled for everyone to meet at 9.30am (the next day). The trade was executed around 9.30 and the first we heard about [the video] was probably 2pm or 3pm [on Wednesday]."

Bird, a premiership player for the Sydney Swans, formed part of the three-way trade which saw Carlisle head to his preferred destination and the Bombers' accrue another top-10 pick.

Kerr said the incident would force the Bombers to speak to their players about the expectations required.

"Obviously Jake has been an Essendon person a long time, so we can't ignore the fact that he did the wrong thing. We've probably got to go back and talk to our group about that and re-emphasise that's not the sort of image and behaviour that we want the players to engage in," Kerr said.

Meanwhile, the Bombers' on-field leadership will be another point of discussion at the club when pre-season training resumes in November.

New coach John Worsfold says the captaincy position is open and that current skipper Jobe Watson would need to go through the process to take on the role for a seventh-straight year.

Watson last year admitted three years in the spotlight of the ASADA/WADA saga had taken its toll and he had lost his enjoyment for the game, and youngster Dyson Heppell stepped into the captaincy while Watson was injured.

"The process is going to be for me to sit down with the whole playing group and coaching staff and talk about what our team philosophy's going to be, what we want to stand for, and how it ties into the club vision," Worsfold said.

"The playing group have already done some work on it prior to me arriving, but I want to challenge them on what it really looks like. Once we know that, we'll know what sort of leader we want.

"That will be one criteria that we'll use in making that decision."