Chelsea have confirmed midfielder Michael Ballack has undergone surgery to cure a nerve problem in his right foot.
The club's announcement, however, contradicts a statement released by the German Football Federation which claimed operations had been carried out on both feet.
But Chelsea's club doctor Bryan English insisted: "He had surgery yesterday morning, a successful procedure, and it will be about two weeks before he is back in training."
He added: "I had a call from the German medical team saying Michael had been playing on Wednesday in quite severe pain down towards the third and fourth toes in his right foot.
"They scanned him the following morning and he had an enlarged nerve in that area which is something that can develop over many weeks and months and suddenly it started giving him pain.
"It is something that if it doesn't give you pain, you leave it alone, but if it gives pain, there is a 20% chance of solving it with injection treatment, but we have taken the option to go for surgery."
Earlier, the German federation had reported the 32-year-old had an operation to remove a neuroma - a benign nerve tumour - from both feet.
National team doctor Hans-Wilhelm Muller-Wohlfahrt told www.dfb.de: "Michael Ballack complained after the World Cup qualifier against Wales on Wednesday repeatedly about strong pains in both feet.
"An MRI scan on Thursday confirmed our suspicions of a neuroma, so after speaking with the club doctor, manager and coach at Chelsea we decided to operate immediately on both feet.
"If the recovery goes normally, Michael will probably be able to return to training in two weeks."
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