Celtic's proposed deal to sign winger Jonny Hayes from Aberdeen has reportedly been complicated by the Dons' desire to take Ryan Christie as part of the transaction.
Brendan Rodgers's side, who last weekend completed an unbeaten domestic treble, are thought to have made a £1m bid for Republic of Ireland international Hayes as they look to strengthen ahead of next season.
Hayes has two years remaining on his current deal at Pittodrie but has been sought by a number of clubs, including Cardiff City and Birmingham City of the Championship, after he scored nine goals and registered 12 assists for the Dons in the league last season.
According to the Daily Mail, Aberdeen are prepared to reluctantly let Hayes go this summer but are keen to see 22-year-old Christie move in the opposite direction as part of the deal.
The newspaper claims that Celtic are unwilling to let the Scotland Under-21s international leave on a permanent deal, however, and will only sanction his return to the Granite City next term on loan.