A man has been arrested on suspicion of assault after Sheffield United captain Billy Sharp was apparently attacked when Nottingham Forest fans spilled on to the pitch at the end of the Sky Bet Championship play-off semi-final.
ottinghamshire Police's chief inspector Paul Hennessy said: "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."
The Blades captain was sidelined for the second leg because of injury and was stood on the touchline after Forest secured a dramatic 3-2 penalty shootout victory following a 3-3 aggregate draw, which precipitated a pitch invasion at the City Ground.
Footage shared on social media, captured by Sky Sports, appears to show one supporter running at the 36-year-old former Forest striker and knocking him to the ground.
Forest have condemned the incident and said in a statement they will "will work with the authorities to locate the individual" and the offender will be subject to "a life ban" from the club.
Sharp said on Wednesday: "One mindless idiot ruined what was an unbelievable night of football.
"Congratulations to Nottingham Forest on their victory and good luck in the final. As an ex Forest player, I will not let one scumbag ruin my respect for the Forest fans.
Sheffield United manager Paul Heckingbottom has called for the fan to be jailed.
He said: "Billy was minding his own business and he was assaulted, blind-sided. It was cowardly. Billy is shaken up and he needed stitches. We have the footage. We always see people talking about player safety but nothing is ever done about it."
Heckingbottom not only provided an update on Sharp but was left furious by incident and made it known in his post-match interview.
"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.
"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.
"How can you come to a place of work minding your own business and be assaulted in that fashion?
"It's just bang out of order and it's everything that's wrong. Too many times we hear people condemn it, but nothing's done about it. We're the ones that suffered.
"It's upsetting for a lot of reasons - I don't want to say too much more about it. He'll be dealt with."
The incident last night was on the same touchline where Forest's greatest manager Brian Clough famously began slapping and punching fans who took part in a pitch invasion in 1989.
The incident overshadowed Forest's win, where the Reds' victory secured a play-off final showdown against Huddersfield on Sunday, May 29 at Wembley Stadium and the chance of a top-flight return for the first time since 1999.
They were pushed all the way there, though, after squandering a two-goal lead. After leading 2-1 from the first leg Brennan Johnson gave them a cushion but second half goals from Blades duo Morgan Gibbs-White and John Fleck pushed the tie to extra-time and then penalties.
Brice Samba, who produced a special point-blank save from Iliman Ndiaye late on, then kept out the spot-kicks of Oliver Norwood, Conor Hourihane and Gibbs-White to the delight of a packed out crowd.
Forest head coach Steve Cooper, who took charge of the club when they were bottom of the second tier last September, said: "To get through a two-legged play-off semi-final, you have to do everything.
"We've managed to come through a lot. I would have loved to have won the game 3-1 and walked off but the fact we've done it like we have means we're more tooled up now to go to the final.
"I promise you I will work even harder than I've worked to get this. No days off, I'll be the first one at the training ground (on Wednesday) and we'll be ready.
"Don't come into something and not aim to be the best, there's no point just competing, especially at this football club - it deserves the best."