It had been reported that the 24-year-old would require surgery to fix the problem, but the Spanish outfit have taken to their website to refute such suggestions.
"1. It is totally false that Bale has that reported injury on his back. 2. The club confirmed that Bale has no injury this Thursday. Surprisingly, the sports daily refused to report this conversation," read the statement.
"3. Bale has a protrusion that is common in many football players. That doesn't affect the normal development of his professional activity."
It is still unclear when the Welshman, who has played just twice since joining from Tottenham Hotspur in the summer, will be fit to return to first-team action.