The Brazilian suffered has expressed his devastation at suffering ankle ligament damage in training at the Allianz Arena on Saturday
The Brazilian suffered ligament damage to his left ankle in training on Saturday and is devastated that he will miss the start of the 2014-15 season.
"I'm very disappointed," Rafinha is quoted as saying by his club's official website.
"I had a really good preparation, and now this. I am very sad."
Rafinha was expected to be sold last summer but went on to establish himself as a first-team regular under new coach Pep Guardiola.
The 28-year-old's injury is therefore a major blow for the Bavarians, but the German champions do, at least, have the option of restoring Philipp Lahm to his more familiar role of right-back, with the World Cup winner having been often utilised as a defensive midfielder during the 2013-14 season.