The spokesperson said detectives were also investigating disorder during the game.
“A number of witnesses have been spoken to and inquiries are continuing,” they said.
Anyone with information is urged to contact Cheshire Police.
A spokesperson for the sport’s governing body, the Rugby Football League (RFL), said it was “aware of events that took place at the game”.
They said the RFL did not condone such behaviour and would “speak with both clubs, following which a thorough investigation will be undertaken”.
Warrington Wolves said the club was “aware of an incident involving one of our supporters that occurred last night, who was taken to hospital and is currently receiving medical care”.
It said it was supporting the family and working closely with police and Widnes Vikings.
Widnes Vikings said the club’s “thoughts are with the individual involved and their family at this time”.