The 22-year-old has made 26 appearances in all competitions for Shamrock Rovers this season and caught the eye of a series of scouts from across the Irish Sea.
Scales has interest from Celtic along with a number of clubs from the Championship, as he looks set to move on from Shamrock Rovers.
It is the Scottish giants who are moving decisively and it is claimed that they are expected to beat Championship clubs to his signature.
Celtic have held talks with Shamrock Rovers and a formal offer has been slapped in, which the Irish side are considering and could potentially be a League of Ireland record sale.
The Scottish side’s owner Dermond Desmond has a 25 per cent stake in the Irish outfit.
Scales has represented the Republic of Ireland at the Under-19 and Under-21 levels and will look to kick on towards the senior team in the coming years.
The defender is tipped to be available for Shamrock Rovers in their Europa League Conference game against Teuta on Thursday.