Birmingham City are expected to dismiss the steward involved in the altercation with Jack Grealish after the Aston Villa star went into the crowd to celebrate his goal at St Andrew's.

Sportsmail can name Paul Fellows as an employee of the club and reveal that he is under serious threat of losing his job for aggressively shoving Grealish as well as team-mate Conor Hourihane.

Birmingham have opened an investigation into the incident, which was caught on camera, and have said they will review all of their 'stewarding, safety and security procedures as a matter of high importance.'

The steward who shoved Jack Grealish during Aston Villa's celebrations on Sunday is expected to be dismissed by Birmingham City

Paul Fellows is under serious threat of losing his job after his heavy-handed response to Villa players who jumped into the stands to celebrate with their fans at St Andrew's

Conor Hourihane and other players reacted angrily as Grealish was pushed by the steward

Fellows and Hourihane can be seen grappling as a police officer tries to intervene

Fellows was not arrested but was spoken to be police officers and is now under investigation

Sky Sports have released a longer clip of scenes following Grealish's 67th minute goal, which shows Fellows apparently kneeing the 23-year-old in the back to get him over the advertising hoardings. Some sources say he was actually trying to get his footing on a step but it is indisputable he pushes Grealish hard, unnecessarily, and also returns to barge Hourihane.

Players are not permitted to enter the crowd and stewards are asked to assist if they do, but Birmingham's hierarchy accept that Fellows' actions were unacceptable. Footage shows Hourihane and Tyrone Mings reacting angrily to Fellows, who was then led off by police. He was not arrested, just spoken to by officers, but he is now the subject of an investigation that is set to see him depart the club, although sources stress no decision has yet been taken.

Meanwhile it can be revealed that the family of Jack Grealish were worried about a pitch invader ahead of Sunday's Second City Derby. It was Grealish's first time playing at St Andrew's and given his profile as Villa's best player and boyhood fan those close to him were concerned something could spark.

They were aware of previous incidents involving fans running onto the field and how last season's game was marred by hundreds of clappers being thrown at Villa players by Birmingham fans.

Jack Grealish scored the winner as Aston Villa won at city rivals Birmingham City on Sunday

Grealish celebrated his goal by jumping into the crowd to share the moment with Villa fans

Family members told friends ahead of the game of their unease. And they were said to be deeply upset when their fears were realised as Paul Mitchell sprinted to attack Grealish from behind.

Mitchell was jailed for 14-weeks and barred from football stadiums for 10 years over the assault, and Birmingham banned him for life. Grealish told police he was 'shocked and scared', adding: 'I can't help feel how lucky I was. It could have been a lot worse if he had a weapon.'

He did manage to shake off the incident to score the winning goal and was training as usual at Bodymoor Heath on Monday and Tuesday. He is set to captain Villa against Nottingham Forest on Wednesday.

Birmingham have taken steps to address poor behaviour. In May 2016 a Stop and Think campaign was launched urging responsible drinking and outlining the threat of prosecution for invading the pitch. In November 2017 the club signed up to the EFL Charter, which hands out three-year bans pyrotechnic-related offences.