Note to Mariah Carey: Tyler Perry wants a note from your doctor.

After the singer dropped out of his latest movie, an adaptation of Ntozake Shange's 1975 play For Colored Girls Who Have Considered Suicide When the Rainbow is Enuf, less than a week before filming was to begin, director Tyler Perry had to cut short his vacation and find a replacement.

"I said, 'What? You're kidding me?,' " Perry writes in a lighthearted new letter to his fans. "It's five days before she has to go to work; nobody does that. We have a deal."

Jetting back to Atlanta where the movie is filming, he selected Thandie Newton to fill Carey's role. (She will join Whoopi Goldberg, Kerry Washington and Janet Jackson in the cast.) Perry also discovered that the singer's doctor was to blame for her sudden departure.

"I was told that we got a call, saying that even though our deal was done, she had been advised by her doctor not to do the film," Perry writes. "I said, 'What? You know I want a doctor's note, don't you? LOL."

As pregnancy rumors surround Carey, her would-be director won't buy into any speculation. "All I know," he writes, "is that I’m waiting just like the rest of the world to find out what happened."

In the end, he doesn't hold Carey's decision against her.

"What I do know of [Carey] is that she is a professional and wouldn't back out of a deal unless it was a major issue," Perry writes. "So, whatever is going on, I wish her and Nick [Cannon] the best and she has all my love, prayers and support."

Jokes Perry: "I just wish I could have finished my Mai Tai before I had to get back and re-cast this role!"