Celtic are the frontrunners to sign Jose Goncalves when his Hearts contract expires at the end of the season.
The Portuguese centre-back is being lined up as a replacement for Parkhead defender Stephen McManus, according to reports, with talks behind the scenes having moved on to quite an advanced stage.
Goncalves has only recently got back into Jim Jefferies' side after being frozen out when he snubbed Heart's new deal offer.
The 24-year-old can sign a pre-contract deal elsewhere because he will be on a 'Bosman' free transfer in the summer.