The 28-year-old has made 159 appearances during that period, scoring 70 goals.
Bale has not played since September 26 but was nearing a return from a calf injury, only to suffer this further setback.
"He has been diagnosed with a strain to the middle third of the adductor longus muscle in his left leg".
Bale has only just been declared fit to return to action for Real after the global break.
"His recovery will continue to be assessed".
Earlier reports suggested that Zinedine Zidane was set to rest Bale for another two weeks before thrusting him back into the first team - but given this latest development, it could be for much longer than that.
Zinedine Zidane and Real Madrid were excited at the prospect of having Bale, Benzema and Cristiano Ronaldo back after the worldwide break but this latest setback put the skids on a BBC reunion for now as further news on the injury is yet to be reported.
Along with the trip to Atleti's Wanda Metropolitano on November 18, Bale will sit out Madrid's next Champions League match against APOEL and may also miss the conclusion of their Group H campaign when Dortmund visit the Santiago Bernabeu on December 6.