Celtic boss Neil Lennon is casting his eye over George Boateng and several other trialists as he looks to build a championship winning squad.
The new boss has already signed two full-backs in South Korea international Cha Du-ri and former Aberdeen player Charlie Mulgrew.
Now he is looking at midfielder Boateng, who arrived at Celtic's Lennoxtown training complex on Monday after being released by Hull City.
The veteran joins Montenegro forward Slaven Stjepanovic, 22, in trying to win a deal while 25-year-old Le Mans full-back Ibrahima Camara is also looking to earn a move to Glasgow.
Assistant manager Johan Mjallby said: "There are a couple of players trying to come in and being on trial. It's a good chance for us to have a look at them training.
"George Boateng has only been here a day and there has been a lot of running.
"Hopefully he can stay on for a couple of days and we can have a look at him playing football as well.
"Slaven has been training for a few days with us. For all the players the first few days has been just running and not too much football.
"We have started to get the balls out now and it's a better chance for us to have a look at them."
Other potential recruits include former England defender Sol Campbell and Cardiff winger Joe Ledley, who have both held talks with the club.