Celtic winger Derk Boerrigter has emerged as an injury doubt for Tuesday's Champions League encounter against Barcelona at Parkhead.
The 26-year-old Dutchman missed training with the Scottish champions on Monday due to an ankle problem.
The complaint could see him sit out the Group H fixture against the Spanish giants.
Celtic have been given a boost ahead of the match with the news that Lionel Messi will be absent for Barca with a thigh strain.