The engergetic midfielder suffered a bad knee injury at the tail end of last season and has struggled to gain a place in the first team. The South Korean international has now rejoined his former club in a bid to keep him place in the national team ahead of this summers World Cup.
The deal is a twelve month loan and Cho will rejoin the Latics in January 2011. The move also frees up more space on the payroll for Martinez to bring in other players.
Speaking to the club's official website Martinez said: "Cho has been a good professional for us, with a great attitude," he said, "and we wish him all the best in his quest to win a place in the South Korea squad for South Africa.
"We hope he performs well for club and country while he is away and look forward to welcoming him back this time next year."