Bayern's Gomez out for a month
The Germany international picked up an injury to his right ankle during Saturday's defeat to Werder Bremen in a pre-season friendly and, after undergoing a scan, it was decided to operate.
Loose bodies in his ankle were removed in the operation and the Bavarian club's doctor Hans-Wilhelm Muller-Wohlfahrt has ordered him to rest for the next three weeks.
"After that, he will then be able to begin light training work again," said Dr Muller-Wohlfahrt.
The 27-year-old will therefore miss the start of the Bundesliga season on 25 August and is doubtful for Bayern's first UEFA Champions League games next month.
He is unavailable to Germany coach Joachim Low for a friendly match with Argentina next week, but the player's priority is getting back to full fitness.
"I am pleased that the operation was a success and that the pain has now gone," said Gomez in a statement. "Now I will need to be a bit patient and then I will do all I can to get back as quickly as possible."
New signings Mario Mandzukic and Claudio Pizarro will be the beneficiaries of Gomez's injury, as they will now get the chance to stake their claims for a starting berth before he returns.