Ozzy Osbourne has reassured fans that he is in good health after cancelling a recent concert.

The 63-year-old rocker - who is married to 'America's Got Talent' judge Sharon Osbourne and fathers children including Kelly and Jack Osbourne - left fans in Germany were fearing the worst when he backed out of a gig with his band a Black Sabbath.

The Germany music event was canceled at the last minute earlier yesterday (20.06.12) however Ozzy only decided against taking part because of ''vocal concerns.''

Sources at the SAP Arena in Mannheim, told TMZ.com that Ozzy was supposed to go on stage after the band Black Label Society finished their set.

But instead of Ozzy, another man announced that he would be unable to perform due to a medical condition.

A representative stated that The Rock legend's overall health is OK and he decided to cancel the show due to issues with his voice.

Concertgoers have been instructed to check the venue's official website to see if Ozzy will reschedule or issue a refund.

The news comes as it has been revealed that his son has been diagnosed with multiple sclerosis.