After months of training, Godsmack frontman Sully Erna has announced that he unfortunately has to pull out of this month’s Rock ‘N’ Roll Marathon.

The band’s official website cites an unspecified injury as the reason behind the singer having to call it quits on the upcoming events.

The post reads: "Unfortunately, because of an injury, Sully has chosen to back out of the San Antonio Marathon on Nov. 11. He plans on continuing his training as soon as he is feeling better and appreciates all the fan support thus far. Fortunately, there will be other marathons in the near future and he looks forward to participating in one of them. He may have to take a little break for now, but he WILL be back in action very soon!"

The Rock ‘N’ Roll Marathon began as just a small race in 1998, and has since turned into a huge collection of running events around the world that rockers participate in to raise money for their favorite charities.

Sully was supposed to run the 26.2 mile marathon in San Antonio, TX on November 11^th in support of his charity 4-LOVE-24, which raises funds for children’s hospitals.

Godsmack also recently canceled a series of European tour dates due to Erna’s vocal issues, but are scheduled to play on the concert cruise ShipRocked with Korn, Five Finger Death Punch, P.O.D, Filter, Black Stone Cherry, Fuel, Pop Evil and others.

The ship launches from Fort Lauderdale, FL on November 27^th and returns December 1^st.

To find out more about the Rock ‘N’ Roll Marathon, click here, and visit the Godsmack official website for further updates on the band.