Saints Academy player Joe Sharratt has suffered serious head injuries and has been been detained in hospital after an incident in Manchester at the weekend.
A club spokesperson said: "We understand GM Police are investigating the matter and therefore we cannot make any further comment at this time.
"Joe is of impeccable character and is an upstanding member of our Academy system. He represented Lancashire Schoolboys against Australian Schoolboys with distinction on Saturday and was hoping to represent England next weekend.
"He is a top academic achiever with a very bright future ahead of him alongside his rugby league prowess.
"Our welfare team are now in contact with Joe’s family and we will offer any assistance we can at this distressing time.
"Understandably, our thoughts are now with Joe and his family.''