By Andrew Holleran The possibility of Jim Harbaugh leaving the University of Michigan for the National Football League appears to be gaining steam. According to a Monday morning report from ESPN NFL insider Jeremy Fowler, Harbaugh has legitimate interest in the Minnesota Vikings head coaching job. Harbaugh reportedly interviewed with the Vikings over the weekend. “Jim Harbaugh conveyed legitimate interest in the Vikings’ head-coaching job during his interview with the team, per source, with Minnesota coming away feeling Harbaugh is ready for a return to the NFL. As of now, he’s still considere…