Wigan Warriors forward Macauley Davies has been forced to retire following the discovery of a pre-existing brain condition.
Scans revealed the 22-year-old has Chiari Malformation, a condition where the lower part of the brain pushes down into the spinal canal.
Davies was sent to see a specialist as part of the return-to-play head injury protocols after sustaining a concussion whilst playing for Swinton Lions when the pre-existing condition was discovered.
"The past three weeks have been the toughest three weeks of my life," Davies said. "From getting a serious concussion and having brain scans my whole world has been turned upside down in what feels like just a few minutes.
"To be told you your dreams of playing rugby league since a little boy is over is the hardest thing I have ever had to hear and to have to make a decision if I want to take a risk and carry on with my dream or to finish it is truly heart-breaking.
"For me the risks are too high and I have no choice - I have to accept that my health and life are more important than continuing to play.
"This is going to take some time if ever to get over and I know it's going to get tougher but I know deep down, if I can put the effort and commitment that I did into rugby then I can achieve anything I want in life. I now need a new career and something I can also pride myself in.
"I'd like to thank Kris Radlinski, Steve McCormack and Chris Brookes. I can't thank them enough for their support through this hard time - it has been first class and to know I've got their support for life means everything to me. Finally to all of my team-mates and coaches, thanks for everything, you mean the world to me."
Wigan Warriors executive director Kris Radlinski added: "We are all desperately sorry for Macauley. He has been a pleasure to work with, deeply committed to represent his hometown team. To have his dreams ruined is heart-breaking for him and his family.
"We are very lucky to have Steve McCormack as our Welfare Manager and he will become so important in Macauley's life as we guide and support him on another career path. Life after sport is inevitable for all players but it is sad when something like this happens to a player at the start of his journey.
"Macauley is a strong individual and I have no doubt that he will go on to be successful in another field."