Rylands Law said it represents a wider group of more than 50 rugby league players, ranging in age from their 20s to their 50s, many of whom are showing symptoms associated with neurological complications.
The RFL said in a statement it has been contacted by solicitors representing a number of former players.
"The RFL takes player safety and welfare extremely seriously, and has been saddened to hear about some of the former players' difficulties," the governing body said. "Rugby League is a contact sport and while there is an element of risk to playing any sport, player welfare is always of paramount importance. As a result of scientific knowledge, the sport of Rugby League continues to improve and develop its approach to concussion, head injury assessment, education, management and prevention across the whole game."
The RFL said it "will continue to use medical evidence and research to reinforce and enhance our approach."
- AP