It was feared the New Zealand-born flanker might never walk again after suffering a serious neck injury in a Premiership game on January 4th.
Fatialofa spent almost three weeks in intensive care in London.
He was then transferred to a rehab unit at the private Royal Buckinghamshire Hospital.
He should have been moved to the NHS Stoke Mandeville hospital next door, but there were no beds available.
And he has now received a bill, reported to be $200,000 for his time at the Royal Buckinghamshire Hospital.
Warriors co-owners Colin Goldring and Jason Whittingham said in a statement: "We are concerned and disappointed to hear that Michael has received a bill for unpaid medical fees.
"We will work closely with the hospital and local Clinical Commissioning Group to understand any issues and help resolve the situation to ensure that Michael can concentrate solely on his rehabilitation at Sixways with the full and continued support of the club."
"We will continue to go over and above what is expected of the club to support Michael and Tatiana financially and practically."
"Michael is also working closely with Lynette Cutting, our excellent Education Officer, on planning for a career away from rugby. We are proud to provide this service to our players and it is one that the vast majority benefit from, helping them to forge successful careers - inside and outside of rugby - once they have stopped, or been forced to stop, playing."
Fatialofa, who played three seasons for the Hurricanes, was actually set to move on this summer to a French Top 14 club when his contract expired.
But Warriors have remained committed to him throughout his rehabilitation so far - and insist that they will continue to do so.