Sydney has added John Blakey to its assistant coaching panel, but the AFL club is adamant it remains unaware of John Longmire's future.

Brisbane announced Blakey would leave the club after working under Leigh Matthews for four years to take up a similar position with Swans coach Paul Roos.

Blakey is the second assistant to leave the Lions in the last few weeks, following Daryn Cresswell's decision to return to Melbourne.

Blakey's move is particularly interesting because Longmire is one of the frontrunners for the senior coaching job at St Kilda.

He had a formal interview with the Saints on Wednesday and it would be his first senior role if he is the successful applicant.

A Swans spokesman said the club would welcome back Longmire if he did not go to St Kilda.

It is understood Sydney will either have an expanded football department if Longmire stays at the club, or give Blakey added responsibilities if Longmire wins the Saints job.

"If I want to further my coaching aspirations, which I do, then it was time to move on after four years," Blakey said in a Lions statement.

"The opportunity was far too good to knock back."

Blakey took over as coach late last year when Matthews was unavailable because of a family bereavement.

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