Jim Harbaugh responds to Tennessee coach's joke with sternly worded tweet

College football coaches just can't seem to stop talking about Jim Harbaugh and Michigan's spring practices at IMG Academy this week. On Thursday, Harbaugh fired back at Tennessee head coach Butch Jones.

Jones garnered Harbaugh's attention after piggybacking on comments from Arkansas coach Bret Bielema and Michigan State coach Mark Dantonio, who suggested they might swing by Michigan's open practice on Friday on their lunch break.

Mind if I join you guys for lunch? @DantonioMark @BretBielema

— Butch Jones (@UTCoachJones) March 2, 2016

Suggestion to my Rocky Top colleague, rather than lunch in Florida you might spend your time and focus attending to your present team.

— Coach Harbaugh (@CoachJim4UM) March 3, 2016

Jones has come under scrutiny after wave upon wave of bad news crashed down on his Volunteer program in recent weeks.

Tennessee football has had multiple recent players arrested this offseason, but no headline has been bigger than the lawsuit filed by six students who accuse several UT athletes of sexual assault. In his testimony, former wide receiver Drae Bowles alleged he was beaten up by his former teammates for helping one of the victims of those assaults. Bowles also alleges Jones called him a "traitor" after discussing the incident with his then-coach.