Adam Cianciarulo was forced to sit out Hangtown on Saturday. Image: Simon Cudby.

Monster Energy/Pro Circuit Kawasaki’s much anticipated rookie Adam Cianciarulo was forced out of Hangtown’s opening round of the 2013 Lucas Oil Pro Motocross Championship with a mystery illness.

The 16-year-old played a big part in the season’s pre-Hangtown press coverage, however he was later admitted to hospital with a temperature that would delay his professional debut.

“This is a huge bummer for me,” Ciancuarulo said. “I’ve been sick all week but the worst of it came at the wrong time. I was admitted to the hospital right after the press ride day.

“The doctors haven’t identified the virus, but I have a 103 temp and haven’t been able to keep any fluids or food down since Monday. If I could race safely I promise you I’d be out there.”

Germany former world champion Ken Roczen went on to win both 250 Class motos to open his 2013 account.

Cianciarulo’s return is yet to be confirmed by Monster Energy Pro Circuit/Kawasaki.