The 38-year-old Gray, who had been with the band since their inception, died last year (May 24, 2010) from an accidental overdose of morphine and fentanyl.
"Donnie was in the band at the very beginning, and rather than get an outsider, we thought it would be a fitting tribute to Paul to play with someone from within the family," the band wrote. "Donnie was great friends with Paul and we can't think of a better way to celebrate his memory than with someone who was there with us at the very beginning. The eight of us are looking forward to being onstage again and honoring Paul's legacy with our families in Europe and Brazil this summer."
Known for their ostentatious performances and aggressive musical edge, the mask-wearing members of the Grammy winning band displayed a different side in an emotional press conference the day after Gray was found dead in an Iowa hotel room, remembering their friend and band mate as "the essence of the band Slipknot," percussionist Shawn Crahan recalled.
"Paul was there from the very, very beginning, and none of us would be on the path that we're on now in life or have the sorts of life that we have without him," he added. "Paul loved the fans. He was kind of the person in the band that really wanted everybody in the band to always get along and just concentrate on the band. He was a really great friend and a really great person. He's going to be sadly missed, and the world is going to be a different place without him."
Among other performances, the band will be performing at the Sonisphere Festival in Sofia, Bulgaria on June 21.