SAN FRANCISCO — The biggest decision the Giants had to make this spring was whether or not Bryce Eldridge would start the 2026 season in the big leagues. Two days before they returned home, they provided the answer. Eldridge was optioned back to Triple-A on Thursday, along with infielder Tyler Fitzgerald and outfielder Grant McCray. The 21-year-old had hoped to crack the Opening Day roster, but instead will return to Sacramento, where he played 66 games last season before a September cameo in the big leagues. The Giants seemed to be split on the decision early in camp, but in recent days it became apparent to even Eldridge’s biggest supporters behind the scenes that he would be heading back to the minor leagues. Eldridge had a solid spring, posting a .830 OPS with his usual batted-ball metrics, and there was a stretch early in March when he was having some of the best at-bats on the roster. But the production had slowed over the last few days, and he had 19 strikeouts in 40 at-bats through Wednesday’s game.Eldridge made huge strides defensively over the past year and now will get to play first base every day, at least early in the season. In...