Jim Harbaugh is most known as the current coach of the Michigan Wolverines, and the former coach of the San Francisco 49ers, where he led the team to within yards of a Super Bowl championship. Brandon Jacobs is known, almost exclusively, as a member of the New York Giants.

The two crossed paths briefly during that Super Bowl season in 2012, as Jacobs signed on as a veteran backup to established RB Frank Gore, where he gained a mere seven yards on five carries.

In nearly any other circumstance, Jacobs would be a forgettable footnote in a legendary season for the 49ers that saw the rise of QB Colin Kaepernick, but this story has recently taken a bizarre turn.

While on the Tiki and Tierney on CBS Sports Radio, Jacobs called Harbaugh’s coaching acumen into question, saying that he has been given too much credit for that 49er team’s success.

“Going somewhere where they don’t have route conversions into certain coverages was just absurd,” said Jacobs. “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. 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.”

Harbaugh then fired back on Twitter on Saturday, throwing shade of biblical proportions:

Jacobs, not to be outworked in the pettiness department, decided to invade Harbaugh’s mentions and asked him to prove his mettle.

Jacobs then (sub)tweeted this statement to his followers, taking the feud up a step beyond the ridiculous level it was already sustaining:

Now the question remains…what does Brandon Jacobs know about Jim Harbaugh that could allegedly get him fired?

Man, the football offseason is fun.