Animation must be marked as legacy... but...

Lol, I know what u guys are thinking, "Omg, this has been answered like 100 times already." I know.

All the other questions and answers that I've looked at are all imported animations. Mine is not, so I can't go to "Rig" and select "Legacy."

(I'm using the 2D tools in Unity 4.3.)

I have an animation which causes the sprite to move which is applied to the sprite's parent.

So how do I mark the animation as legacy if I haven't imported the animation? Thanks.