For the past few weeks reasonably scary tales about Marc Marquez’s broken arm have been leaking from Spain.

What do we know in terms of verifiable facts?
Marc Marquez broke his right humerus in the first race of the season at Jerez. He underwent surgery after the race and had the broken upper right arm plated.
Initially, Marquez’s injury seemed to be the typical “merely a flesh wound” he has suffered a number of times in his career. Injuries that would stop a normal rider, but with Marquez they do very little to slow him down. Being out for five weeks, initially, seemed reasonable; but within days of leaving the surgery theater Marquez believed he was strong enough to come back for Jerez 2.
Marquez was laughing his way through the FIM med checks on his injured arm. However after he rode his Honda MotoGP bike in practice, he returned home and another surgery was scheduled as the titanium plate in his arm broke. He underwent a second surgery in early August to put in a new unbroken plate.
And, since then, it’s been pretty quiet. No videos of Marc doing push ups, boxing with a heavy bag or taking part in any professional ice skating rounds where he’d loft his partner over his head during pirouettes. Marquez sat out the entire 2020 season. As of a week ago he was still moving his injured arm very carefully and wasn’t talking in any specifics in terms of a return date.
Unverifiable rumors from Spain:
That the Marquez injury has not healed more than 20-30% in four months. There remains substantial weakness in Marquez’s upper arm.
That during the second surgery a partial bone graft was performed on the break when the surgeons replaced the broken titanium plate. The bone graft material did not come from Marquez’s hip; the surgeons used cadaver bone to graft the area.
And, so goes the rumor, the bone graft and Marquez’s body don’t seem compatible. Meaning a third (complete?) “do over” surgery may be required. But now the injury isn’t a clear cut, freshly broken bone. It’s a hot mess of partially-healed bone, a slurry of un-accepted graft and ti-plate. Worst case scenario is it may take additional months to heal. Or all of 2021.