User blog comment:Rassilon of Old/Young Justice spoilers at Comic-Con 2012/@comment-4967138-20120717181048/@comment-1038387-20120717182329

There are only two.... Red Arrow was/is 21. Zatanna and Rocket were the newest members, 25 and 26.

Leaves us with 22, 23, 24.

One of those three has to be Black Lightning. So, two left.