Originally Posted by Paubri
This happens to me all the time to/from ONT. You may already know this, but don't purchase the ticket to SNA and skip the LAX-SNA segment or United will cancel the rest of your itinerary.
But you can always get a shuttle van to SNA on the way out, and then discard the LAX-SNA final leg on the return, as there is no rest of itinerary to cancel.