A man arrested after Llanelli's Gavin Quinnell lost the sight in his left eye due to an injury in a rugby match will not face criminal charges.
Gwent Police arrested an unnamed 26-year-old Cross Keys player on suspicion of assault following a game in October.
But the force said following advice from the Crown Prosecution Service no charges would be brought.
Mr Quinnell is the son of ex-Wales and British Lions player Derek and brother of ex-internationals Scott and Craig.
He had surgery after the game on 2 October but doctors were unable to save the sight in one eye, ending his professional career.
He had recently re-signed for the Scarlets, having spent two years at Worcester and two years at Italian Super 10 side Viadana.
Quinnell was playing for Llanelli in the Welsh Premiership against Cross Keys at the time.
In a statement Gwent Police said: "Following Crown Prosecution Service advice the 26-year-old man arrested on suspicion of assault has been released with no further action."
A spokesperson for the Scarlets said: "It is hugely disappointing that Gavin can no longer pursue his career as a professional rugby player as a result of the injury he sustained, but he has shown great spirit, dignity and bravery throughout and continues to look positively forward to the next stage of his life and what his options are.
"At present Gavin is still receiving treatment from a specialist eye consultant based at the Heath hospital in Cardiff and will continue to be monitored.
"The family's focus and priority has always been on Gavin, his welbeing and future path, and the Scarlets will continue to provide their support in any way possible."