Brandon Jacobs seems to still be quite bitter about his time with the San Francisco 49ers under Jim Harbaugh. Days after he ripped into Harbaugh for having “no idea” about football, the former NFL running back tweeted a message saying Michigan will fire Harbaugh by the time Jacobs is done exposing him.

https://twitter.com/gatorboyrb/status/868574910515490817

Of course, perhaps this comment was sparked in part by Harbaugh’s response to Jacobs on Saturday morning.

This all got started when Jacobs made an appearance on CBS Sports Radio.

“Jim, I had a lot of respect for Jim when I was there – before I got to know him,” Jacobs said on CBS Sports Radio. “I enjoyed my time there, but we didn’t see eye-to-eye.

“I knew a little bit more about football than what they led on,” Jacobs continued. “Going somewhere where they don’t have route conversions into certain coverages was just absurd. 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.”

Jabobs signed with the 49ers in 2012, which was the season the team ended up losing to the Baltimore Ravens in Super Bowl XLVII. He was barely utilized that season after a knee injury kept him from doing anything until October of that season.

After a string of bitter social media posts in which he bemoaned his status as a bench warmer, Jacobs was ultimately suspended the final three games of the season. He’s been an avid Harbaugh hater ever since, these recent comments just being the latest in a long line.