Of course, he’s currently starring as Shadow Moon on American Gods, but since that’s a premium cable show with less episodes compared to something on broadcast, that would presumably allow more freedom in his schedule to take on Green Lantern Corps (not to mention that there’s no word yet on if the Starz show will get a third season).
Ricky Whittle is clearly interested in getting to be Green Lantern, so maybe he sends a better than most of obtaining the role.
Remember that just because an actor has had conversations with people working on a movie doesn’t mean that said actor will necessarily obtain the role, but it’s definitely a step up from campaigning to play a character.