We recently told you guys that rapper Nicki Minaj would be joining Rihanna and Pop newcomer Ke$ha on Ri’s upcoming “Last Girls on Earth” Tour this summer, but Nicki announced today via her Twitter that she will not be joining Rihanna and Ke$ha on tour so that she can put the finishing touches on her debut album, which is also set to be released this summer.

This is probably a good move for the hot female rapper considering that she still needs to complete her album and actually put it out. Doing a major tour around the world with Rihanna would likely hinder that process, unless she’s up for working overtime!

No word from Rihanna’s camp just yet as to who will replace Nicki or if they’ll just leave it as Rihanna & Ke$ha on the bill.