Chelsea´s German midfielder Michael Ballack could be considered for the club´s USA tour despite preparing to undergo further surgery on his ankle on Tuesday.
Ballack injured his ankle and underwent an operation in May but complications with the healing of the wound have forced him back into hospital.
A spokesman for Chelsea confirmed: "Michael Ballack will have an operation in Germany tomorrow on his ankle. The operation is related only to a complication in the healing of the wound from previous surgery in May."
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