As a former Collingwood rookie, Hartley received only a one-year deal after being drafted by the Dons in November, rather than the standard two-year contract given to draftees. But impressed by his season to date, it's understood the Bombers have moved to secure Hartley, who was restricted by injuries to just five VFL games in two seasons at Collingwood.

In the absence of the suspended Michael Hurley, Cale Hooker and Tayte Pears, the retired Dustin Fletcher and the traded Jake Carlisle, Hartley has been given ample opportunities in defence this season, and has impressed.

In a difficult year for the club, he has emerged – along with elevated rookie Anthony McDonald Tipungwuti and top-up player Matt Dea – as a valuable discovery.

Having made his debut in the round two win over Melbourne, Hartley, 23, has been a senior mainstay in the 12 games he has played. Arguably his best performance came in last Sunday's narrow loss to St Kilda, in which he broke the Dons' record for one-percenters. It also earned Hartley a spot in the AFL's team of the week.

While the terms of a new deal remain subject to further negotiation, it's believed Hartley wants to stay with the Bombers, who plucked the 198 centimetre New South Welshman from VFL club Coburg.

The Dons must carefully manage their salary cap given their desire to retain all 12 of the players suspended in January by the Court of Arbitration for Sport. While Hooker, Travis Colyer, David Myers, Dyson Heppell, Tom Bellchambers and Heath Hocking have all re-signed, the Bombers are still waiting on Pears, Hurley, Brent Stanton, Jobe Watson, Ben Howlett and Michael Hibberd to re-commit.

It appears unlikely that all of the remaining six will stay at the club, with defender Pears eyeing a career in firefighting. Hibberd's future also remains unclear, with the running defender a target of Melbourne.

Bombers coach John Worsfold said the club would need to know what was happening with the dozen banned players before looking at possible trades.

"There will be a timeline. We haven't set that yet, but obviously there will be a final date that we'll need to know in terms of our decision making, but that's a way off," Worsfold said. "Ultimately we do need to know what the squad will look like.

When those decisions have to be made around our current list, we'll need to know what the intent is from the other guys. That's still a fair way off." Worsfold said the Dons were keen to keep Hibberd.

"We're really keen to have Michael here and part of what we're building. It's going to be hugely exciting and he'll look good in our backline next year."

The Dons take on Richmond at the MCG on Saturday as they try to snap a 13-game losing streak.

Key forward Joe Daniher's goalkicking remains an issue, with the spearhead having kicked 24.22 for the season. But Worsfold said he remained confident Daniher could improve.

"I'm confident Joe's aware of what he needs to do to improve his accuracy and he's working pretty hard on it."