Celtic are closing in on a deal for Jonny Hayes and have reportedly agreed a fee of over £1 million with Aberdeen for the winger.
The Dons would also get Ryan Christie on a season-long loan deal as part of the transfer.
Celtic midfielder Christie spent the second half of last season on loan at Pittodrie.
Hayes, 29, is well known to Celtic manager Brendan Rodgers who worked with the player when he was a coach at Reading.
His likely departure will come as a real blow to Aberdeen who have already lost key players Ryan Jack, Niall McGinn, Ash Taylor and Peter Pawlett.
Manager Derek McInnes is also close to leaving for Sunderland.