The victims were scattered across the fields of the NFL in 2013, and included Sam Bradford, Jay Cutler, E.J. Manuel, Brian Hoyer, Terrelle Pryor, Christian Ponder, Jake Locker and Michael Vick.The best-laid plans of NFL teams were wrecked, or severely changed, by injuries to starting quarterbacks last season. So, as the 49ers transitioned from 2013 to 2014, they believed they needed to have a better option than Colt McCoy as the primary backup to starter Colin Kaepernick. If Kaepernick should go down this season, head coach Jim Harbaugh and offensive coordinator Greg Roman wanted a quarterback who could continue to operate the 49ers' offense and get them to the playoffs.So in early March San Francisco traded a sixth-round draft pick for Jacksonville quarterback Blaine Gabbert, who had been the 10th overall choice of the 2011 draft, but had devolved from promising starter to injured and struggling player in 2013. Last season, the 6-foot-4, 235-pounder from Missouri played just three games, completed only 48.8 percent of his throws and had seven interceptions against just one touchdown pass, just two seasons removed from a solid rookie year when he had 12 TD throws in 15 games.But...