Mary J. Blige and Chris Brown

Mary J. Blige and Chris Brown will not perform at the Michael Jackson tribute concert in Vienna later this month, Rolling Stone reports.

Concert organizers previously announced Blige and Brown as participants at the event, but Blige's rep told Rolling Stone the singer has a prior commitment at a Gucci show in Milan.

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Blige was in talks to perform at the concert, but Brown, however, was never in real talks, a source told the magazine. "To say it was even being considered was a stretch. He was not close to saying yes," the source said, adding that the 20-year-old would need permission to travel overseas since he's been sentenced to five years of probation for his assault on Rihanna.

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Brown's name was tossed around to "drum up attention" because the other acts weren't big names, the source said. The lineup includes Akon, Natalie Cole, Sister Sledge and German boy band US5.  

The concert will be held Sept. 26 at the Schoenbrunn.