The 28 year old has featured just 13 times for the Latics since joining in the summer and has managed just a solitary goal against Blackpool.
“We are in advanced talks with Deportivo La Coruna for Oriol to go there on loan,” revealed Mackay.
“We felt it’s in the best interests of both parties and hopefully something will be tied up in the next day or two.”
Reira hasn't had the desired impact on the first team with the physical nature of the English game appearing to get the better of him during his initial months with the Latics.
His departure will free up wages in the first team squad for Mackay to make a similar loan move as replacement.