Nicki Minaj Thinks American Idol Producers Set Up Mariah Drama?

Sources connected with Nicki tell us ... she's convinced producers -- along with member's of Mariah's team -- are conspiring to get under her skin ... because they think a pissed off Minaj will bring in viewers.

We're told Nicki is adamant ... she won't be anyone's puppet and if she feels she's being set up, she vows to "cut it off at the head." As for how, she says for starters, the next time Mariah "acts up," Nicki is walking off the set.