The 30-year-old has been blighted by knee problems and last played first-team football in the 2009/10 season.
He has been training with his first club ADO Den Haag back in his homeland and will now be reunited at Wigan with Martinez, who is giving little away for the time being about the prospect of the player signing a deal at the DW Stadium.
"It is just having him training, for him to see how he feels and how the knee reacts," Martinez said.
"It is just to see how he gets back into shape, nothing else.
"I always said he was the best player in his generation and it has been a real shame that out of the players that started something special at Swansea, he is the only one who has not played in the Premier League.
"I hope that one day he can get that reward. But that is a long way off.
"It is important that he gets himself fully fit and sees how he feels. We are going to try to help him in that respect and see if he is fully recovered."