London - Jonathan Joseph says he played in England's Rugby World Cup games against Australia and Uruguay with only one third of his chest muscle attached to the bone.
Joseph's pectoral muscle was torn during the World Cup opener against Fiji and the centre was subsequently ruled out of the next fixture against Wales.
He appeared to heal quickly however and started against Australia before stepping off the bench for Uruguay.
But when Joseph's injury was scanned on his return to his English Premiership club Bath, the full extent of the damage was revealed.
"I felt something in my pec and wasn't too happy about it as I'd done the other pec before and it felt a little bit similar," Joseph said.
"When I got back to Bath, they had a little play with it. I had felt something in there during the Uruguay week but wasn't too concerned.
"Bath had it scanned and in fact I only had about a third of the muscle still attached.
"Although I could feel it against Australia and Uruguay, it wasn't too bad. I was aware of it, it was strapped but I managed to tackle all right.
"It was a World Cup and I was going to do everything I could to play. Obviously, I wasn't aware that there was only one third attached."
Joseph's return from surgery against Northampton last weekend was a full month ahead of schedule and he makes his second club appearance of the season in Sunday's European Champions Cup clash with Wasps.