I doubt it's a hybrid. Longear can have about the same type of green stripes on the face as green sunfish, and redbreasts to a lesser extent.
Unless it's a redbreastxlongear, and I don't think I could definitively ID one of those.
I've kept a ton of longear and I could still see it being one of those. The thing that makes me question that ID is that longear generally have color that extends completely around the gill spot, and yours stops at the end on both sides. Whereas redbreast commonly do not have color all the way around the gillspot.
But I've also seen longear where the gill spot looks exactly like yours (and the females often have a smaller, shorter spot).
But the gillspot being slightly elongated, pointing upward, and also the lack of other green sunfish traits (including the caudal and pectoral fins being shaped wrong - and the dorsal fin appears to be set too far back), still makes me think it's NOT a greenie.