Neil Warnock has told BBC Wales that Sunderland's swoop for Derek McInnes could be the reason why the Irish winger has stalled on a move away from Pittodrie.
Sunderland have been linked with a swoop for Hayes should McInnes make the switch to Wearside. He provided the most assists (12) in the Scottish Premier League in 2016/17, as well as nine goals.
The Black Cats are short of wide players and Hayes is unlikely to cost a premium.Warnock, who has been after Hayes ever since joining Cardiff City last year, has given up on sealing a deal for the 29-year-old.
Hayes is still expected to join Brendan Rodgers at Celtic, with the Dons hopeful of signing Ryan Christie, who spent the second half of last season on loan with McInnes, as part of the deal.
Warnock said: "You can only wait for so long and you've got to move on.
"Aberdeen want two players from Celtic and they've been messing us around for quite a few weeks now.
"And it wouldn't surprise me if their manager Derek McInnes goes to Sunderland either - so there might be other motives behind everything stalling.
"We've moved on and gone on to another one or two targets that haven't been mentioned yet."