The Australia winger, 29, joined Saudi Arabian club Al-Faisaly in January and Hibs are in "dialogue" over his return.

"That doesn't necessarily equate into a signing," said Johnson.

"We've got dialogue with four or five at the moment in various positions because we're still active in the market.

"Of course, we'd love to bring Martin here. It won't be cheap. It would have to take a big investment from the ownership. We need an addition in the position, there's no doubting that.

"Most deals are complex. I think what the club's done is put themselves in a position that if Martin ever becomes available, we're at the front of the queue.

"The club have got to want to move him on and at the moment, we just don't know the full facts on that matter."

Johnson is relishing his first derby in charge of Hibs having rebounded from a group-stage League Cup exit by beating St Johnstone in the Scottish Premiership opener a week ago.

Two of last season's Edinburgh derbies finished 0-0 but Hearts won the final league meeting and the Scottish Cup semi-final meeting.

"I'm really looking forward to it," said Johnson. "When you sign for a club like Hibs, with a history, with the stature of the club, the first fixture you look for is the Hearts game.

"When it was early, I was very excited by that. The players are very excited. The game takes care of itself motivationally.

"It's been too long. I want an experience of listening to our fans singing Sunshine on Leith and this is the first opportunity to be able to have that.

"We're going to be have to be tactically very astute because of their qualities and also the players that we've got out. We're ready for it, we're well prepared."

Meanwhile, Hibs full-back and midfielder Chris Cadden, 25, has signed a new contract tying him to the club until the summer of 2025.