An injury plagued 18 months has seen the talented midfielder play only 6 times and the potters have missed the 25 year olds ability and presence in the first team.
Boss Johan Boskamp told Stoke's website: "They have to clean out his knee and hopefully then everything will go quicker.
"We hope he is back with Clint Hill at Christmas. It's frustrating for them and us but we have to wait."
4 important first team players are currently side-lined, including Hill and Eustace but also new signings Sammy Bangoura and Hannes Sigurdsson, who should both make their debuts much sooner than christmas.