Leeds Carnegie centre James Tincknell is seriously ill in hospital after suffering head injuries in a car crash near the border of Cumbria and Durham.
Tincknell, 22, is in a medically-induced coma after Monday's crash on the A66.
He was travelling back to Leeds for training in what police described as "appalling weather conditions" after staying with his family in Cumbria.
Tincknell is one of rugby union's most highly rated young players.
Six other vehicles came off the road at the same location at Stainmore summit.
In a statement, the Aviva Premiership outfit said: "The club would like to ask all supporters to keep in their thoughts centre James Tincknell, who was involved in a car accident on Monday morning.
"James is currently in intensive care, however he is in a stable condition and the club are in contact with his family to offer any support they require."
Tincknell is being treated at Middlesbrough's James Cook Hospital.
Police said there was freezing fog and rain at the time of the crash and the road was unsafe because of black ice.