According to Turkish outlet Aksam, Celtic are keen on bringing Beşiktaş centre-back Duško Tošić to Parkhead this January and have already tabled a £2.6million bid.
However, the Turkish giants are holding out for £3.5million for the 32-year-old Serbia international, and it remains to be seen if the Hoops will return to the negotiations table.
Manager Brendan Rodgers is looking for reinforcements at centre-back, and the loan departure of Erik Sviatchenko to Midtjylland makes Celtic thin in the department.
While the arrival of Marvin Compper from RB Leipzig was supposed to help add depth, Celtic have been dealt a huge blow as the German has been ruled out for at least a month following an injury.
With that reality check, Rodgers knows another centre-back remains top priority, and could be forced to return for an improved bid for Tošić.
The former Werder Bremen and QPR man has loads of experience, with over 340 league games to boot.
Tosic also played a huge role in helping Besiktas to the last 2 Süper Lig titles, and will be a great addition to Celtic.