After two seasons of knocking back bids for Scott McKenna, the Scotland international is set to exit Pittodrie.
The 23-year-old was withdrawn from the squad for the 3-0 shocker against Motherwell following a “significant offer” from Championship Nottingham Forest.
As McKenna travelled south for contract talks, Dons boss Derek McInnes admits both clubs were close to agreeing a deal for the centre-back.
It is understood that fee will be £3 million plus add-ons, which would eclipse the previous club record for a sale which has stood for more than two decades.
That was the £1.75m received from then top-flight Coventry City for Eoin Jess in 1996.
McInnes confirmed there will be no cash from a transfer fee made available to strengthen the squad as plans had already been put in place for a potential exit of McKenna by the signing of Ross McCrorie and Tommie Hoban.
Asked if there would be scope to strengthen following McKenna’s sale, the Aberdeen boss said: “No. We made succession planning with Ross McCrorie and Tommie Hoban coming in short term.
“That was on the thought process that Scott would maybe move this summer.
“We were allowed to bring Tommie in on a short-term deal and Ross in as part of the process in dealing with Scott leaving.”
Aberdeen rejected a £6.5m approach from Aston Villa on summer transfer deadline day in 2018. They also rejected a £3m bid from Forest last year.
McKenna slapped in a transfer request last summer after bids from Forest, QPR and Sheffield Wednesday were knocked back.
It was no surprise to McInnes when there was fresh interest in the defender, capped 16 times by Scotland.
Especially in light of his recent form, which McInnes believes people would have “had to be living on Mars” not to notice.
He said: “We weren’t encouraging bids, but were expecting bids once the Championship got up and running.
“The way Scott’s form has been you would need to have been living on Mars to not see how fantastic he has been. His stats are right up there with anybody in our league. I’m pretty sure they’re close to a fee being agreed and Scott is on his way down south.
“I’d be surprised if it fell through. Scott was always going to move at some point.
“He’s a player with 16 caps and at the age of 23 he’s only going to improve.”
With McKenna at the heart of the defence, Aberdeen had conceded just once in a six-game winning streak going into the clash with a Motherwell bottom of the league prior to kick-off.
In just 23 minute,s a defence minus McKenna shipped three goals. It was a major setback, with the Europa League third qualifying round tie at Sporting Lisbon looming on Thursday.
In a further blow McInnes confirmed winger Matty Kennedy would miss that clash in Lisbon with a knee injury.
McInnes said: “The decision was made in the morning that Scott wouldn’t play.
“Tommie Hoban cannot play Thursday and Sunday, although we brought him on at half-time.
“Making two changes to a back three isn’t ideal. Certainly when we needed to defend we didn’t when losing three in 20 minutes.
“Clearly not winning a header in the box will always be an issue.
“The first goal Motherwell kept it alive for the penalty kick.
“The second goal was an uncharacteristic mistake from big Joe.
“Ash should probably have played the ball forwards and perhaps indicative of where we didn’t react well to first goal. The third goal was offside but it was neither here nor there to the result.”