Bundesliga side Mainz are hoping to beat Celtic to the signing of AEK Athens goalkeeper Vasilios Barkas and are understood to have made an approach for the Greek international.
Reports in Greece claim that the 05ers have made contact with the player's representatives.
It was reported earlier this week that Celtic recruitment chief Nick Hammond was hoping to use his network in Greece to explore a potential deal for the 25-year-old, who has been identified as a potential replacement for Fraser Forster.
AEK have dropped the ten-cap Greek international for their last three games, even though he had been a starter before then and is contracted until the summer of 2022.
Mainz conceded eight to RB Leipzig last weekend and have shipped 27 goals in just ten league games, which may explain their interest in Barkas.
Shankland on the radar?
Celtic scouts are understood to be preparing a dossier on Lawrence Shankland ahead of the January transfer window.
The Dundee United ace has hit 17 goals in 15 games for Robbie Neilson's side after joining in the summer and earned his first Scotland call-up.
Now the Hoops are set to run the rule over the 24-year-old, having been linked with him in the past.