Sky Sports News understands Celtic are in talks to bring in Mallorca defender Ivan Ramis on a permanent deal.
Celtic manager Tony Mowbray is keen to bring in a right-sided centre-half and has lined up a move for Ramis.
The 25-year-old came through the ranks at Mallorca and has spent his entire career with the club, aside from a spell on loan at Real Valladolid during the 2005/06 season.
He could now be on his way to the Scottish Premier League after the Bhoys opened negotiations with Mallorca.
Ramis is still under contract, so would command a transfer fee, although it is unclear how much the stopper will cost.
The potential arrival of Ramis at Parkhead will help to solidify a Celtic defence that has seen Gary Caldwell join Wigan Athletic and Stephen McManus head to Middlesbrough during the transfer window.
Danny Fox has also left the club to join Burnley, while Mowbray has brought in Jos Hooiveld to further boost his options at the back.