He spent a season playing baseball for the Grand Forks Chiefs; a Class C minor league team in the Pittsburgh Pirates organization.
Bud Grant convinced Hackbart to drop baseball and concentrate on a career in the National Football League.
He asserted that a late hit by Cincinnati Bengals running back Boobie Clark was an intentional tort.
Billy Thompson, who was playing left corner for the Broncos, jumped in front of me and Boobie Clark and intercepted the pass.
When I came up on to one knee watching Thompson run the ball, Boobie came up from behind me and whacked me in the back of the head, with a right fore-arm and drove me into the ground, after the Play was finished.
He did not seek medical attention, but the continued pain caused him to report this fact and the incident to the Bronco trainer who gave him treatment.
In the case the courts ruled that in the course of a professional football game an intentional infliction of an injury by one player upon another might constitute a tort.
Hackbart settled with the Bengals and the Broncos filed a Workman's Compensation claim which paid for the surgery that was performed in 1976.