​Few would have seen the San Francisco Giants’ shockingly poor first half coming. The second half, then, is anyone’s guess.On paper, the Giants should have been better than last year, adding Luis Arraez to the lineup and improving the defense. The bullpen’s drawbacks were known, the lack of another top-flight starter acknowledged. Add to that superb efforts from Arraez, Casey Schmitt, Jung Hoo Lee and Bryce Eldridge, and it’d be tough to imagine a team battling to stay out of the last place.AdvertisementAdvertisementAdvertisementThe abysmal first half will have some ramifications, though, that could mean that any hope of a big second-half surge is all the less likely. The Giants are likely to – and probably should – move pending free agents Arraez, Robbie Ray and if possible, Tyler Mahle, for prospects. They’d certainly be tempted to move one or more of the high-priced infield trio – Rafael Devers, Willy Adames, Matt Chapman – were a trade partner dangling particularly attractive prospects or, more to the point, willing to pick a significant chunk of the remaining salary owed on their contracts.That’s disappointing, of course. Arraez has been a joy to watch, Ray is the proverbial Mike Krukow-style “Good Giant.” But any selloff by a team 19 ½ games out in the NL West is practical. The only question is how many players the team might lose.After a rough first half, the prospect of going younger is exciting. Rookies Eldridge and Victor Bericoto have been two of the most fun stories of the season, along with Schmitt’s development into an everyday player. The winning percentage might not improve much with a young movement, but getting experience for some top prospects or maybe even some new acquisitions would be a realistic goal.An Arraez deal would hand Schmitt a regular spot in the lineup at second base. Moving an older outfielder, say Harrison Bader, would ensure playing time for Bericoto. Carson Whisenhunt could move into the rotation should Ray head elsewhere. Blade Tidwell would be worth a long look as well.AdvertisementAdvertisementAdvertisementAny veterans remaining would be well advised to do two things: finish strong and be exemplary role models for the next generation of Giants. Fair or not, leadership from players, manager, coaches and execs has been a question mark because of the team’s first-half flop, and it would be a great idea for the older players to leave zero doubt about their desire and ability to lead.As for the leadership elsewhere, it is, of course, not uncommon for managers to bear the brunt of a bad season. Three managers have already been fired this season: Boston’s Alex Cora, Phillies manager Rob Thomson and Carlos Mendoza of the Mets, but none of the five rookie managers has been dismissed. Tony Vitello came in with zero experience in pro ball; canning him for that lack would be unfair, and there have been no indications the front office has considered such a move or that team execs are unhappy with him.Could there be