The NRL today wished Newcastle Knights forward Alex McKinnon a full recovery from his injury sustained in last night's match in Melbourne.

NRL CEO, Mr Dave Smith, said the thoughts of the entire Rugby League community were with Alex, his family and friends.

"The doctors have advised that it will be a number of days or weeks until the extent of his injury is known," Mr Smith said.

"The NRL and the League community will do whatever we can to support Alex and his family during this time."

Mr Smith said spinal injuries were extremely rare in Rugby League and it was clear that everyone on the field last night was distressed at Alex's injury.

"At this time our entire focus is on Alex's wellbeing and we wish him a full recovery," Mr Smith said.