Bristol Rovers manager Joey Barton has gone on trial accused of assaulting a fellow football boss after a match.
Former England international Barton, 38, is accused of assaulting former Barnsley boss Daniel Stendel, causing him actual bodily harm (ABH), after a game between the Tykes and Fleetwood at Oakwell in April 2019.
Barton denies the charge and a trial began at Sheffield Crown Court on Monday 7 June.
Twelve jurors were selected after they were screened to determine whether they recognised or had heard of Joey Barton, had any opinions of him, or whether they supported Barnsley or Fleetwood Town.
Barton, who was in charge at Fleetwood Town at the time, is accused of pushing Stendel in the tunnel after a League One match which Barnsley won 4-2.
Watch Joey Barton arrive at Sheffield Crown Court
In his opening statement prosecutor Ian Goldsack said Stendel sustained serious injuries to his mouth, including a tooth being moved back from the bone and associated nerve damage.
He told the court the defendant chased after Stendel in the tunnel area after the game, before pushing him from behind which caused him to fall and hit his face.
Mr Goldstack said Barton "ran past a number of people" and entered the tunnel behind Mr Stendel.
He added: "Mr Stendel felt a push from behind and fell forward, hitting his face against part of the tunnel structure.
"He looked up and saw the defendant passing him.
The court heard very few people witnessed what happened but one eyewitness - Barnsley's first team performance analyst intern Nathan Kirby - provided a statement.
Mr Goldstack said Mr Kirby described being a few paces behind Mr Stendel as they entered the tunnel when Barton ran past him before deliberately pushing Mr Stendel and knocking him off balance.
The jury were shown video footage of the moments before and after the alleged incident, which the prosecution says support Mr Kirby's claims.
Mr Goldsack told the court Barton used foul language towards Mr Stendel at the end of the game before the alleged incident took place. He said Mr Stendel, who is German and whose first language is not English, did not fully understand what he was saying but realised he was being insulted.
In a written statement given to police after his arrest, Barton accepted using what he called "industrial language" while at the touchline but denied barging into or otherwise assaulting Mr Stendel.
In his statement, Barton said if he had pushed Mr Stendel over he would have known about it.
Mr Stendel was not present for the opening day of the trial and will be giving his evidence via video link from Germany on the morning of day two.
The trial continues.