User blog comment:Thailog/Ep. 207 "Depths" discussion/@comment-4956038-20120715175423/@comment-4821105-20120716073138

Raven and Starfire who never members of Young Justice. And all most members already made his/her debut

Superboy was a member of Young Justice since season 1

Red Tornado is one heroes that suports the team.

Secret debut on episode "Secrets"

Arrowette debut on episode "Insecurities"

Robin (Tim Drake) is member of the team since season 2

Wonder Girl (Cassie Sandmask) is memberof the team since season 2

Impulse made his debut in episode "Bloodlines"

The only members that never made his/her debut are Slobo (clone of Lobo), Empress and Ray.