Australian all rounder Bradley McGee has been forced out of the national team for the world cycling road race championships which begin here Wednesday due to a back injury.

The 29-year-old McGee, due to compete in the 273km road race on Sunday, has been replaced by Brett Lancaster.

Lancaster, 26, was a member of the Australian team which claimed Olympic pursuit gold in a world record time at Athens last year. His road credentials are impressive also, having worn the Giro d’Italia’s pink jersey for winning the race prologue earlier this summer.

Simon Gerrans' late call-up to the Cyclones squad came after Rory Sutherland's recent suspension by his professional team Rabobank after the 23-year-old tested positive for a banned substance at the Tour of Germany.

The results of an 'A' sample emerged only a few days ago. A 'B' sample is currently being tested, and Rabobank stressed the product used was not the banned blood booster EPO (Erythropoietin), nor a blood doping transfusion. Gerrans, a first year professional in Europe, showed his capabilities on his Tour de France debut this year. The 25-year-old, who rides for the AG2R team, finished the race and came close to claiming a prestigious victory on stage 17.

On Thursday Michael Rogers will launch the Aussies' bid when he defends his world time trial crown in the men's 44km race against the clock. Rogers is the two-time reigning champion.

Sunday's road race will also provide the ever-improving Aussie contingent with another chance at gold in the men's road race, in which Robbie McEwen is a big favorite along with Italian Alessandro Petacchi and Belgian Tom Boonen.