According to F4WOnline.com, while John Cena has been telling people publicly that he is aiming for a WrestleMania 30 WWE return, officials are privately discussing his return for the Royal Rumble in 2014, which will be about 5 months from his surgery, and in the 4-6 month return time frame.

Mysterio Appears at WWE Live Event
Rey Mysterio appeared in front of the live crowd at last night's WWE Live Event in Fresno, CA. He told fans he will be returning to TV in September.

Good for Rey!

...as he was leaving for the back, he injured himself.

I heard Rey got a serious injury while he was busy getting injured. :/

^You aren't funny. <_<

^I don't recall saying I was, nor never forced anyone to laugh, nod or approve of what I post, sir.
But I thank you for your completely relevant opinion on this subject.