Japan international midfielder Hiroki Yamada has started training with Scottish champions Celtic ahead of a possible move.
Manager Neil Lennon revealed earlier this month that he was eager to take the 24-year-old on trial.
Yamada, who has two caps at international level, currently plays his club football for J-League side Jubilo Iwata.
Celtic continue their defence of their Scottish Premiership title on Saturday when they play host to Hearts.