The Dons are pursuing Gary Mackay-Steven.
Aberdeen are hopeful they may be able to sign the Celtic winger in time to play in the Europa League second qualifying round.
The Reds take on NK Siroki Brijeg of Bosnia and Herzegovina on Thursday at Pittodrie in the first leg of the tie.
The deadline for registering players for the game was 11pm on Friday, but one wildcard player can still be registered up to 24 hours before the match.
Although that means a deal has to struck by tomorrow evening the Dons are still hopeful that it could be completed in time.
Derek McInnes is a long term admirer of the former Dundee United man and is prepared to do business with Celtic again after Aberdeen sold Jonny Hayes to the Hoops and Ryan Christie came to Pittodrie on a season-long loan.
The Reds brought in a late loan signing before the Europa League second qualifying round last season when they snapped up Wes Burns on loan from Bristol City hours before they beat Ventspils of Latvia 3-0 in the Europa League at Pittodrie –with Burns coming off the bench to score.
Aberdeen have already taken attacker Christie on loan from the Parkhead club, which means they would have to bring Mackay-Steven in on a permanent deal.
But with the former Liverpool, Airdrie and Ross County man under contract until 2019, it would take a massive bid from the Dons to land him permanently.
It is believed Mackay-Steven wants to leave the treble winners after becoming frustrated by a lack of game time.
Last season he appeared just 10 times.
McInnes has a policy of not commenting on transfer speculation until deals have been completed.
But he does want to sign a quick, wide player to help replace Hayes and Niall McGinn, who left at the end of last season and last week joined South Korean side FC Gwangju.
McInnes told the Evening Express on Monday he wanted to sign a player in the mould of Hayes and McGinn.
He said: “I don’t want to speak about any specific players.
“We have made offers and approaches for several players over the past few weeks and we will see.
“I have been open about the positions we are trying to fill.
“We are also looking at bringing in a wide player. A natural wide player, a ball carrier.”
Mackay-Steven has also been heavily linked with English Championship side Sheffield United, but it appears Aberdeen are in pole position to sign the 26-year-old.
The Dons were also linked with Mackay-Steven in May but a deal could not be agreed at that stage.
If he does come to the Granite City, Mackay-Steven will give McInnes a multitude of attacking options.
This summer, Aberdeen have signed Christie, midfielder Greg Tansey from Inverness Caledonian Thistle, attacker Greg Stewart on loan for the season from English Championship side Birmingham City and striker Nicky Maynard.
They are also still hopeful of signing Scotland international Shaun Maloney, but that will be after the tie with Siroki Brijeg as the Aberdeen-raised attacker has an injury concern.
Aberdeen have also had two bids rejected by Motherwell for their striker Louis Moult.