John Francis, 34, pleaded guilty at Pudsey magistrates court, West Yorkshire, to wounding Paul Stephenson. He was also ordered to complete 150 hours community service and pay pounds 50 costs.
Francis, of Leeds, played for Sheffield United and Burnley before joining local league side Farsley Celtic, near Leeds. The court was told that Francis and Mr Stephenson were at the club's bar in September celebrating the manager's birthday. Francis was having an argument with his girlfriend outside when Mr Stephenson left and Francis hit him.
Catherine Dowson,for the prosecution, said: "The blow knocked him to the floor and fractured the complainant's jaw in two places."
In mitigation the defence said it was a one-off incident that was out of character act.