Getty Images Holly Marie Combs is claiming Alyssa Milano threatened to sue the higher-ups of Charmed if Shannen Doherty wasn’t fired from the WB series. “[Producer Jonathan Levin] said, ‘We didn’t mean to [fire Shannen], but we’ve been backed into this corner. We’re basically in this position where it’s one or the other,’” Combs, 50, recalled during the Monday, December 18, episode of Doherty’s “Let’s Be Clear” podcast. “‘We were told [by Alyssa] it’s her or [Shannen] and Alyssa has threatened t