I think I know why Star Sapphire was used and not Sinestro

[Batman 80]

I was at DC page recently and they had a bio for the DC heroes that also stated who their main enemies were. I found John Stewart and Sinestro was not listed as his main enemy. Star Sapphire was. This is why I think she is being used(I don't mind she looks great in the animated style).

[austin norsworthy]

as impulse would say, kewl!

[Karkull]

Well, I don't know if John Stewart ever fought Sinestro, but since Hal Jordan isn't around he sort of becomes John's enemy by default.

I've read that Sinestro might appear in Season Two.