"It's not a fair exchange," said Ozzy Osbourne, referring to former Metallica bassist Jason Newsted's joining his band to replace Robert Trujillo, who quit last month to join Metallica. "It's robbery, I say."

"He is a great bass player, has a good attitude in my band -- and I have no hard feelings with Robert Trujillo," explained Osbourne, who officially welcomed Newsted to his band with a private, four-song rehearsal for some twenty-five writers and photographers Monday afternoon at 3rd Encore Studios in North Hollywood, California.

Newsted, who left Metallica after fourteen years in January 2001, will actually be doing double duty on Ozzfest 2003, as his other band, Voivod, has just been added to the second stage. Voivod, who hail from Canada, will also play Osbourne's upcoming Canadian tour.

"This is something I'm doing first out of respect, so it took zero seconds [to decide]," said Newsted, who first jammed with Osbourne's band last Sunday and says he's played his fingerprints off already. "As for the physical part, I will push myself to make this happen . . . It's a huge blessing."

If Monday's rehearsal is any indication, metal fans won't even miss the departed Trujillo, whose last show was Friday at the Hard Rock Hotel in Las Vegas. Newsted slipped into the Osbourne bass position seamlessly as the band powered through Black Sabbath's "War Pigs," and three Osbourne hits, "Believer," "No More Tears" and the classic "Crazy Train."

And it looks like Newsted's new alliance with the Prince of Darkness won't stop at this summer's tour dates. When asked if they'd be writing new material together, Osbourne was quick to reply, "Absolutely. I can't wait . . . This TV thing has stopped me of my rock & roll."

In related news, Ozzy's wife and manager Sharon Osbourne had a bit of a spell at Friday's Vegas show. In answer to reports that she was taken out of the venue on a stretcher, Osbourne explained, "No, she's recently just got through with her chemotherapy . . . She was fine. It was the excitement, the heat of the crowd, the noise. She's still kind of delicate. I refer to her now as the unstoppable Sharon, because one minute she's fucking at death's door and the next minute she's fucking running up the road buying a house."

As previously reported, Ozzfest 2003 will get underway on June 28th at Verizon Wireless Amphitheater in San Antonio, Texas.

Osbourne's pre-Ozzfest Canadian dates:

6/1: Vancouver, General Motors Place
6/4: Calgary, Pengrowth Saddledome
6/6: Edmonton, Skyreach Center
6/8: Winnipeg, Winnipeg Arena
6/11: Toronto, Air Canada Center
6/12: Ottawa, Corel Center
6/14: Montreal, Bell Center
6/16: Quebec City, Colisee Pepsi

Written by CARRIE BORZILLO-VRENNA for RollingStone.com News