Head coach Jim Harbaugh was let go after feuding with General Manager Trent Baalke and CEO Jed York. Potential Hall of Famers Justin Smith and Patrick Willis retired. Willis’ replacement, linebacker Chris Borland, retired after just one season due to concerns with concussions. As if those losses were not enough, a host of prominent Niners players (Frank Gore, Michael Crabtree, Mike Iupati, etc) conducted an exodus during free agency, further crippling a team that was just two seasons removed from a Super Bowl appearance.