Japan attacking midfielder Hiroki Yamada is training with Celtic this week, the Scottish champions revealed on their website on Tuesday.
The 24-year-old, who plays for Jubilo Iwata in Japan, has won two international caps this year and Celtic manager Neil Lennon has expressed admiration for him.
"We're looking to bring him over to take a look at him," Lennon told Scottish newspaper the Daily Record earlier this month.
"(Head scout) John Park has watched him a couple of times and we've seen some footage. However, it's always good to see him up against the rest of the players and how he copes with it.
"He can play left side or off the striker. He looks OK, but we'll not have a real idea until we've seen him over here. I don't think there would be any money involved -- he's a free (transfer)."