Brandon Jacobs and Jim Harbaugh spent one year together, in 2012, Harbaugh as the head coach of the San Francisco 49ers and Jacobs as a little-used running back.
And what a horrible year that was, at least in Jacobs's perspective.
While the Niners were on their way to a Super Bowl appearance, Jacobs appeared in only two games with five total touches -- down from 242 touches in 15 games just three years prior.
Jacobs was so disgruntled he sent this tweet out in November of that year, which he swore definitely wasn't about Harbaugh.
Anyway, Jacobs left after one year to return to the Giants and Harbaugh eventually left for Michigan. End of story, right? I mean, what animosity could Jacobs possibly have toward a guy who coached him for one year half a decade ago?
A lot, it turns out.
"They’re just running routes in the defense, getting people killed. Size and strength is what they had, and that’s why they won. Let’s be real," Jacobs said in an interview with CBS Sports radio. "They had great assistant coaches, but Jim didn’t know what he was doing. Jim had no idea. Jim is throwing slants into Cover-2 safeties, getting people hurt. That guy knew nothing, man."
Those comments were just the beginning of Jacobs's crusade, apparently. "I will expose him, Michigan will fire him when I am done," he wrote in a since-deleted tweet on Saturday.
Harbaugh noticed Jacobs's comments and resisted his Donald Trump-like instincts to fight fire with fire, opting instead to dump water on his former player's enflamed takes.
On behalf of college football writers and observers everywhere, here's hoping Jacobs's crusade is unsuccessful.