Rangers boss Stuart McCall says he feels sorry for Newcastle loanee Gael Bigirimana, but admits he should never have been signed by the Ibrox club.
Burundi-born England youth cap Bigirimana has yet to feature for the Light Blues after being diagnosed with a mystery illness.
He was one of five Magpies youngsters signed by former Rangers chief executive Derek Llambias without being put through a medical - even though Bigirimana knew he was sick before signing for the Glasgow giants.
The 21-year-old has denied rumours claiming he is suffering from Hepatitis-C, but Gers boss McCall confirmed his condition means he will not be able to feature for his adopted club.
"Bigi has got a medical condition which is a personal matter," said McCall. "The doctor and consultant are all involved in that.
"I knew him at Coventry. I remember watching him and thought when I came into the job he will be a good one to bring in and give us a bit of energy. Unfortunately because of his medical condition he won't be able to play for us.
"But that is as big a blow to the kid as it is for us. It's not his fault, this [row] has been nothing to do with him. He comes in with a smile on his face each morning, he trains with the fitness coach as hard as he possibly can.
"So as disappointed as we are that we can't use him, you have to think of the boy in this matter because he can't go back, he can't play for anyone else.
"It's an unfortunate circumstance that really should never have happened."
Llambias - a close associate of Magpies owner Mike Ashley - signed off on the five Newcastle loan deals just hours before the January transfer window shut, but did not ask club doctors to check the players over.
So far only Slovenian playmaker Haris Vuckic has played regularly.
Defender Remie Streete limped off just half an hour into his debut and has not been seen since, while Northern Ireland winger Shane Ferguson has yet to even step foot inside Murray Park after being ruled out for the rest of the season with a serious knee injury.
Swiss defender Kevin Mbabu has featured for Rangers' youth side but is "nowhere" near being fit enough for first-team duty, according to McCall.
The Gers boss cans sympathise with the players but hit out at the previous regime's decision to sanction some of the signings.
McCall said: "Should these guys ever have been sent here? Well, with Bigi being unable to play that's a no-brainer. With Shane, he was on his way back but had a little setback.
"But I think if you look at it in all honesty, anybody who comes up for a six-month loan should have a medical - obviously that is not the case.
"If that had occurred, two or three of the loans may not have happened.
"But none of the players are at fault here. Shane has not been up but the rest come in and train as hard as they can. They are doing their utmost to be involved."