LOS ANGELES — There was only one logical landing spot for the first home run of Bryce Eldridge‘s career. On Monday, two days after he hit it, Eldridge flashed a wide smile and said the souvenir is headed for his mom’s house.The rest of his Mother’s Day weekend and the surrounding days, however, were puzzling. Eldridge was out of the starting lineup on Friday and then hit an impressive homer down the right field line on Saturday. His reward was a spot on the bench to start Sunday’s game, and when the Giants showed up at Dodger Stadium on Monday, he was again out of the lineup.During his pregame session with reporters, manager Tony Vitello spent most of his time answering questions about the 21-year-old top prospect. Asked to define Eldridge’s role, he said he’s “a threat.” He didn’t talk in absolutes, but said a three-day window without a start “would be a painful pill to swallow.”Mostly, the answers left the impression that Eldridge’s primary job, at least right now, is to pinch-hit.“I’m hopeful it would be almost every game, and (he would) at least get one at-bat,” Vitello...