German rock band Scorpions have been forced to cancel their appearance at tonight's Def Leppard gig due to illness.

The group were set to open for Def Leppard at tonight's Rod Laver Arena show, which will still go ahead. 

"We came a long way to finally rock Australia for the very first time (except for Melbourne)," said Scorpions‘ co-founder and lead singer Klaus Meine.

"Together with our friends Def Leppard, we have had a fantastic run so far and it breaks my heart to let you know that I can’t sing tonight at the Rod Laver Arena in Melbourne.

"The doc has recommended that I rest my voice until Sydney and I cross my fingers that it all works out."

The tour's next scheduled stop is at Sydney's ICC on Saturday.