The South Australian has played 97 games in the gold and brown across his tenure at the Hawks, including a career-high 19 appearances this year.
O'Brien could find himself venturing back to his home state in a move to Alberton, with the Power potentially looking to utilise the Mount Gambier product as a forward-defence utility, according to Edmund's report.
“Port Adelaide is one of the clubs that have enquired about Tim O’Brien, possibly even as a defender I’ve been told but clearly he can play forward as well," Edmund said.
“He would offer some insurance up forward for Charlie Dixon, it’s very early in the process here and if it does come to fruition, you’d think it would be later rather than sooner.
“But Port Adelaide has come knocking for Tim O’Brien.”
The Power already boast strong tall targets in attack, with Dixon and young pair Mitch Georgiades and Todd Marshall aiding Ken Hinkley's side to a preliminary final finish for the second-straight season.