John Mayer has hired Lady Gaga's former employee, Troy Carter, as his new manager. The Daughters hitmaker split from his manager Michael McDonald in December (13) after 13 years together, and now he is teaming up with Carter, who left Gaga's team in November (13). A source tells Rolling Stone that the pair has known each other for years, and his hiring marks the first time Carter, who primarily has managed pop and hip-hop artists, will work with a major rock musician. There has been much speculation around Carter's split from Gaga, with rumours that the the two parted ways over "creative differences." Gaga even recently alluded to the "betrayal" she felt after a hip injury sidelined her last year (13), citing some close professional relationships broke down after people "lied and worked me into the ground for their personal gain."