ANN ARBOR, MI - SEPTEMBER 24: Michigan Wolverines head coach Jim Harbaugh shouts out instructions during the first quarter of the game against the Penn State Nittany Lions at Michigan Stadium on September 24, 2016 in Ann Arbor, Michigan. (Photo by Leon Halip/Getty Images)

SEC player on Jim Harbaugh: "Michigan will fire him"

He was still feeling it.

There are plenty of people out there who do not like Michigan coach Jim Harbaugh for whatever reason. However, there's one former player of his and former Auburn running back in Brandon Jacobs who does not like Harbaugh at all. He previously said in an interview that Harbaugh had no idea what he was doing in San Francisco. Now, he's gone one step further.

RELATED: Brandon Jacobs on Harbaugh's 49ers tenure: "(He) didn't know what he was doing"

Harbaugh heard about Jacobs trash talking him and took to Twitter to let him know how he felt about it.

Of course, Jacobs wasn't going to be outdone and tweeted out a couple more things for the coach:

That might have gone a step too far. You can certainly get lucky once or twice as a coach, but to get to the Super Bowl on just luck and not knowing anything as Jacobs would suggest is pretty ridiculous. Not to mention he went down to the college game and has had immediate success as well. While you might be able to "fake it 'til you make it" you can't fake it after you've made it for as long as Harbaugh has now.

[h/t SEC Country]