Footage has emerged showing a football fan headbutting an opposition team's striker to the floor after their play-off semi-final victory.
On Tuesday night, Nottingham Forest defeated Sheffield United 3-2 on penalties after the second leg of their EFL Championship play-off semi-final ended 2-1 to produce an aggregate score of 3-3.
Forest will now take on Huddersfield United in the final of play-offs to see which team will join Fulham and Bournemouth in the Premier League next season.
The Tricky Trees now stand a chance to play in the English top flight for the first time since 1999 as they head to Wembley Stadium, but their victory over the Blades was marred by an overzealous Forest fan.
Billy Sharp, a former Forest player himself, was seen on the sideline in the moments following his side's loss. While standing still, he was headbutted by an onrushing supporter, who seemed to lower his shoulder into the Blades star, who then dropped to the ground as the fan ran away.
Sheffield United manager Paul Heckingbottom said after the match that Sharp was injured during the pitch invasion.
"We're seeing things thrown on the pitch and things that are thrown on putting players' health and safety in danger, and nothing's ever done about it," the Blades boss said, as per the Daily Mail.
"There will be something done about that. We've seen what's happened, we know what's happened. There's a prison sentence there, without a doubt."
Nottinghamshire Police have confirmed the arrest of a man on suspicion of assault, and that a full investigation into the incident at the City Ground is underway.
Paul Hennessy, chief inspector of Nottinghamshire Police, said in a statement: "A 31-year-old man has been arrested on suspicion of assault in connection with this incident. He remains in custody and will be questioned by officers.
"Our enquiries into the circumstances surrounding the incident are ongoing. We have spoken to the player concerned and we are working with both clubs, who are supporting us with our investigation."
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