To Dave Roberts, the roster crunch facing the Dodgers might be a good problem to have. But the situation still presents a problem. The good news for the club: Mookie Betts is set to be activated from the injured list Monday, making his awaited return from an oblique strain that has sidelined him for more than a month. What that means, however, is that someone will have to be squeezed off the active roster in a corresponding move. And on the eve of that decision Sunday, no easy answer had yet