Kevin Nisbet is due to undergo a medical at Millwall after Hibernian accepted a bid of around £2m for the Scottish striker.
The Championship club previously offered just over £1million for the 25-year-old.
Nisbet, with 10 international caps and one goal, has scored seven times in seven Hibs appearances this season.
Meanwhile, Ryan Porteous is still finalizing a deal with Watford and was not at Hibs practice on Friday.
Aberdeen visits Easter Road during Saturday’s Scottish Premiership game.
The terms of Nisbet’s proposed move to Millwall would be life changing for the player, who has just returned from surgery for a knee injury.
He joined Scottish Premiership club Dunfermline Athletic for £250,000 in July 2020, having scored 23 goals in 32 appearances for the Fife club.
The Glasgowian has since played 88 times for Hibs, scoring 34 times, which has sparked interest from the club sitting eighth in the English second tier.
Millwall are looking to strengthen their frontline after selling Isaac Olaofe to Stockport County and terminating fellow striker Benik Afobe’s contract this month.
