Worcester Warriors say that Michael Fatialofa will continue to have the club's full support in a disagreement over unpaid medical fees.
It was feared the New Zealand-born flanker, 27, might never walk again after suffering a serious neck injury in a Premiership game on 4 January.
Fatialofa spent almost three weeks in intensive care in London.
He was then transferred to a rehab unit at the private Royal Buckinghamshire Hospital 40 miles away in Aylesbury.
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 for his time at the Royal Bucks, prior to him being discharged and allowed to return home to Worcester on 5 June.
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."
Fatialofa 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.
The BBC have approached the Royal Buckinghamshire Hospital for a response.
The background to the fight over fees
Fatialofa suffered his injury - a C4 vertebrae fracture and spinal contusion - when joining a maul less than a minute after coming on against Saracens as a second-half replacement at Allianz Park on 4 January.
The club helped set up a fund-raising appeal which, as of Monday 6 July, had reached £40,702.
But the amount owed in medical fees is understood to be at least double that sum.
Fatialofa has been welcomed back to Sixways, where he continues to have use of the club's facilities to help him follow a rehabilitation programme supervised by the club's head of medical Ryan Kehoe.
And Worcester are baffled at why the player himself has been landed with the bill.
A club statement added: "The club was asked to fund the first two to three weeks of private treatment in the Royal Buckinghamshire Private Hospital next door which benefited from the same consultants and had beds available.
"The club agreed to pay for four weeks in case it was needed through the RugbyCare scheme, which spreads the cost for the club.
"At the expiry of the four weeks the NHS were still not ready to provide a bed and Royal Bucks had to continue providing care until the NHS was ready to transfer Michael.
"In situations such as this a claim is made to the Clinical Commissioning Group which the club's doctor, Nick Tait, made sure was done.
"The club heard nothing further and RugbyCare have confirmed they were never asked to authorise or fund a further extension by the Royal Bucks."