The 53-year-old rocker reportedly cracked his vertebrae - a bone in his spine - in the incident, which occurred while he was performing at the Caribana festival in Crans-pres-Celigny, Switzerland last Thursday (02Jun16)l.
Editors at Scotland's Daily Record report that as well as sustaining the back injury, Bobby, 53, split his head open in the fall from a speaker, which occurred 40 minutes into the band's set and saw him carried away on a stretcher.
After being treated in a Swiss hospital he was flown home on Tuesday (07Jun16) on an air ambulance plane.
According to the paper, the Loaded singer has been ordered by doctors to take complete bed rest by lying flat on his back while the injury heals.
The band posted a photograph of the singer in the plane returning him to the U.K. on their Facebook page with the caption, "FEEL LIKE GOING HOME".
The news over the severity of Bobby's condition, which is not life threatening, means a number of the band's upcoming gigs are now in doubt.
Primal Scream are due to play two dates in Spain and two in Ireland before the end of June (16), with another gig scheduled for 2 July (16) in Cluses, France.
They then have a 13 day break before they are scheduled to resume their European tour by playing Britain's Beat-Herder festival in Sawley, England on 15 July (16).
Representatives of the band tell WENN that an announcement on whether the gigs will go ahead will be made on Wednesday (08Jun16).