Celtic boss Neil Lennon has refused to be drawn on speculation linking the Hoops with a move for Filip Benkovic.
The Leicester City defender spent last season on loan at Celtic and has been made available for another loan move this month.
Bristol City are interested in the 22-year-old, but the Robins face competition from Championship rivals Derby County, with Celtic also said to be interested in taking the Croatian back on loan.
Middlesbrough are the latest club to have joined the race for the centre-back.
Lennon would not be drawn on whether Benkovic would return to Celtic, but did not rule out any interest in the Robins target.
"I don’t know is the answer," Lennon told The Scotsman.
He added: "I only worked with Filip for a short term, but I know he had a good impact here last season, so hopefully we’ll be looking to bring one or two in this week."
