The Dons are hoping to complete the signing of Celtic midfielder Gary Mackay-Steven before tomorrow’s Europa League deadline.
Aberdeen have already signed midfielder Ryan Christie on a season’s loan after a successful six-month stint last term.
SPFL rules stipulate a team can’t loan more than one player to another club within the same division so the Dons would have to sign the player on a permanent basis if the deal is to be concluded.
Dons manager Derek McInnes believes his side is lacking width following the departures of Jonny Hayes to Celtic and Niall McGinn, who joined South Korean side Gwangju last week, and hopes Mackay-Steven will fill the void.
Mackay-Steven joined Celtic in a £250,000 move in February 2015 but has rarely featured under Brendan Rodgers, starting only five games for the Hoops last season.
The Thurso-born player, 26, began his career at Ross County before spending two years at Liverpool but was released after suffering several injuries.
He spent time with Fulham before returning to Scotland and joining third-tier Airdrie United in 2011 before moving to Tannadice six months later.
Newly-promoted English Championship club Sheffield United were the favourites to sign the Scotland international on a permanent basis but the Dons held talks with the player at the weekend.
Aberdeen can add one player to their squad for their two-legged Europa League encounter against Bosnian club NK Siroki Brijeg by midnight tomorrow.
This month Mackay-Steven said he was determined to compete for his future at Celtic.
He said: “I am always confident in my own ability. When I’m fit and healthy I feel I am more than good enough to play, so it’s just a case of getting the confidence of being in good physical shape to know I am going to manage 90 minutes, and that only comes with runs of games.
“In terms of confidence and my ability and playing wise, it’s never been a doubt in my mind.”
Hearts midfielder Sam Nicholson, who had been linked with Aberdeen, ended any prospect of a move to Pittodrie by signing a two-and-a-half year contract with MLS side Minnesota United yesterday.
The Dons have sold 11,000 tickets for Thursday’s match against NK Siroki Brijeg at Pittodrie.
Former Aberdeen loan forward Simon Church is training with Hibernian.
The Wales international is a free agent after being released by Dutch side Roda JC Kerkrade.
The 28-year-old scored six goals in 13 games during a loan spell at Pittodrie during the 2015-16 campaign.