The back-and-forth spat between Brandon Jacobs and Jim Harbaugh continues.

It was Jacobs – a former running back on Harbaugh’s 2012 San Francisco 49ers team – who fired the first shots on the Tiki and Tierney Show earlier this week. In the radio interview, he claimed that Harbaugh “didn’t know what he was doing.”

After catching wind of that statement, Harbaugh, of course, retorted with some biblical advice for Jacobs.

Harbaugh’s response didn’t sit well with Jacobs, it seems. On Saturday night, Jacobs sent out a tweet, vowing that Michigan would fire its head coach after Jacobs “exposes him.”

Since playing in San Francisco, Jacobs has been relatively hostile towards his former coach.

Jacobs only appeared in two games with the 49ers and had just seven rushing yards for the year. For someone as loud as Jacobs, you can understand why limited playing time would be an issue.

But this back-and-forth between Jacobs and Harbaugh is starting to look more like middle-school trash talk. Maybe both guys will go their separate ways and set differences aside.

Nah, probably not.