Ozzy Osbourne [ tickets ] has completed a heavy-metal flip-flop by enlisting former Metallica [ tickets ] bassist Jason Newsted to fill the hole left by bassist Robert Trujillo, who recently became Newsted's replacement in Metallica.

Osbourne announced on Monday (3/17) that Newsted would round out his backing-band lineup, which also includes longtime Ozzy guitarist Zakk Wylde and former Faith No More drummer Michael Bordin. Osbourne made the announcement at his rehearsal space in North Hollywood, where he and his band are gearing up for this summer's Ozzfest tour. A pair of pictures that show Newsted and Osbourne together are posted at the official Ozzfest website.

Newsted left Metallica in January of 2001, citing "private and personal reasons, and the physical damage that I have done to myself over the years while playing the music that I love." At the time, he called the move "the most difficult decision of my life."

The bassist will be pulling double-duty on Ozzfest, as he also is a member of second-stage act Voivod.

Osbourne was forced to search for a bassist after Metallica announced in late February that Trujillo was the band's new four-stringer. The new Metallica lineup will make its live debut during the upcoming Summer Sanitarium tour, which kicks off in July and will support the band's forthcoming album, "St. Anger."

In related Ozzfest news, organizers announced on Monday (3/17) that Trust Company has dropped off of the bill in order to begin work on a new album. No replacement act has been named.