Brett Houlsworth, aged 29, of Wadsworth Avenue, Intake, admitted the offence after the friendly match between Grimsby Town and the Blades on July 23.
The wider violence saw six arrests with one man sustaining serious injuries.
Humberside Police undertook a huge operation to avert trouble from rival fans but supporters clashed at various different points across the day in the seaside town.
Grimsby Magistrates’ Court heard Houlsworth was ‘unhappy’ that his uncle was being ‘held in a headlock’ by another officer during the incident at Cleethorpes train station.
The court heard that Houlsworth, a roofer by trade, had a ticket for the game but decided not to attend and stayed in the town drinking.
Defending solicitor Nick Furman, told the court his client said the officers were ‘heavy handed’ and Houlsworth was not involved in any disorder prior to his incident.
He added his client suffered a cut to his head and his lip.
The defendant admitted assaulting the officer and was handed an 18-month conditional discharge. He will not be allowed to attend any football game in the UK or abroad for three years as part of the banning order.
Another Sheffield United fan appeared in the same court charged with a different offence.
Perry Smith, 30, of Garland Close, Westfield pleaded not guilty to a charge of assault by beating.
The charge relates to an incident inside Grimsby Town’s Blundell Park stadium where it’s alleged Mr Smith assaulted a fellow Sheffield United supporter.
Grimsby Town FC said efforts to work with Humberside Police to control disorder at the game ‘failed miserably’.
Humberside Police said its officers were ‘brought on duty early’ to assist in the wider operation’.