WWE Diva AJ Lee is currently on the sidelines with an injury. She had previously been working hurt so that WWE could wrap up her feud with WWE Divas Champion Nikki Bella.
WWE originally intended to do a significant injury angle to write her off of television, but for whatever reason those plans were scrapped.
Lee being away is also said to be the main reason why Naomi and Natalya were moved into title contention. Original plans were going to be Naomi going for Bella’s title, however they may be leaning towards Natalya at this point.
As far as AJ Lee is concerned, the belief among those in the company is that she will be back at some point in 2015.