Manager Paul Jewell seems pretty keen on signing the 31 year old and sees his fitness as the only potential stumbling block.
He told the club's official website: "Stephane brings a wealth of Premiership and international experience and would be a great signing for us.
"He's training with us for the rest of this week and then hopefully something will happen when we get back home to England. He doesn't have to prove anything in terms of quality; all he has to prove is his fitness.
"He's been training on his own all summer, but from what I've seen so far he's kept himself in pretty good shape."
Should the Swiss international sign for the Latics, he would join Pascal Chimbonda and Ryan Taylor as new additions to the defence.
Ze Castro is also expected to sign shortly from Portugal.