Big Ten commissioner Tony Petitti sent a 13-page letter to Michigan athletic director Warde Manuel on Friday outlining why the league has handed down a three-game suspension for Michigan coach Jim Harbaugh.

While the letter states that Michigan never denied the existence of what the B1G viewed as an “impermissible, in-person scouting operation over multiple years,” the conference admitted it has no evidence to prove whether or not Harbaugh knew of the operation.

From the letter:

We impose this disciplinary action even though the Conference has not yet received any information indicating that Head Football Coach Harbaugh was aware of the impermissible nature of the sign-stealing scheme. This is not a sanction of Coach Harbaugh. It is a sanction against the University that, under the extraordinary circumstances presented by this offensive conduct, best fits the violation because: (1) it preserves the ability of the University’s football student-athletes to continue competing; and (2) it recognizes that the Head Coach embodies the University for purposes of its football program

Harbaugh will be eligible to work with the team throughout the week of practice leading up to games, but he will be barred from being present at the game venue on gamedays over the last three weeks of the regular season.

That will leave Michigan without its head coach for games against No. 10 Penn State, Maryland, and No. 1 Ohio State.

“The University’s November 8 response does not deny that the impermissible scheme occurred. Instead, it offers only procedural and technical arguments designed to delay accountability,” the B1G said in its letter. “Taking immediate action is appropriate and necessary under the Conference’s Sportsmanship Policy.”

Michigan said in a statement it plans to seek “immediate judicial relief.”