Hoops chief scout John Park had the Libertad star watched last week when Paraguay faced Austria in a friendly and have also had him followed over the past month as his Paraguayan club reached the semifinals of the Copa Libertadores.

However, Celtic chose to turn their attentions elsewhere this week.

Apart from Riveros, the ambitious Glasgow giants are ready to build their profile in South America and have also been in contact with the agent of Spartak Moscow's Brazil international Mozart.