Casting HBO's Green Lantern Corps

Diego Boneta is a fairly unknown actor, one that hasn't had a massive amount of opportunity to show audiences what he can do.

This choice for him to play Kyle Rayner is admittedly based off of very little: the fun and charm he brought even to tiny roles like his appearance in Terminator: Dark Fate, his relative youth (to help convey that Rayner is a rookie) and, of course, his very good hair (please ignore the trim he has in the picture above).

Plenty of lesser known actors have had numerous small roles before being given a far more central character to play, if DC decided to make him Rayner at some point in the future then this could simply end up as another one of those cases.