Aston Villa captain Jack Grealish says he was “lucky” that the supporter who attacked him during Sunday’s derby match against Birmingham was not carrying a weapon.

Grealish was punched by Birmingham fan Paul Mitchell, 27, who on Monday was jailed for 14 weeks and banned from all football stadiums for 10 years at Birmingham Magistrates’ Court.

In a statement read into the court record by prosecutor Jonathan Purser, Grealish said: “I cannot help but feel how lucky I was in this incident.

“It could have been so much worse had the supporter had some sort of weapon.”

The Football Association said on Monday afternoon that “a line had been crossed” with this incident and a similar one later the same day where a supporter came onto the pitch during the Arsenal v Manchester United match and pushed United defender Chris Smalling.

“This weekend a line has been crossed in terms of fan behaviour. On Sunday we saw two separate incidents, at Birmingham City and Arsenal, of individuals entering the field of play and assaulting players,” the FA statement read.

“Not only is it an offence to enter the pitch, which could result in a club ban and criminal charges for the individual, but it also puts the safety of the players at risk. This is entirely unacceptable and we strongly condemn both incidents.

“We will be working with the clubs, the leagues and the police to discuss what collectively needs to be done to protect players and officials on the pitch.

“In addition, we have written to both Birmingham City and Arsenal to seek their observations and examine the security measures they had in place.”

Birmingham announced on Monday that they had banned Mitchell from St Andrew’s for life, and the club have also banned another supporter for the same term “for a series of vile and malicious tweets on social media, relating to Jack Grealish and his family”.

A club statement added: “Birmingham City FC rejects all forms of anti-social behaviour. We will not tolerate the kind of incidents we have seen during and since Sunday’s derby fixture against Aston Villa Football Club.”

Professional Footballers’ Association chief executive Gordon Taylor has called the attack on Grealish “disgraceful” and “cowardly” and believes the authorities must work with the government to help stamp out such incidents.

After a spate of attacks, Taylor insists the authorities must “put a lid on the problem” quickly and he has called on the Football Association to work with the government, police and stewards at the grounds to help eradicate such behaviour.

“It was disgraceful, cowardly and criminal. We have seen an increase in such behaviour at clubs this season. It’s been racist abuse, it’s been anti-Semitism and now it’s real fear for the safety of players,” Taylor told Sky Sports News.

Minister for Sport Mims Davies called the incidents “a disgrace” and added: “It is right that they are investigated immediately and strong action is taken by the football authorities and clubs.

“Protecting players’ safety is of paramount importance and every possible step must be taken to ensure that they are not put at risk.”

Birmingham defender Harlee Dean told Press Association Sport after the match: “You should never fear for your safety on a football pitch and it’s disappointing to see.

“There’s a lot of hate amongst the fans and stuff, which is fine to an extent, but you shouldn’t be able to come on the pitch and make contact with a player.”

Former England striker Alan Shearer has warned players’ lives could be at risk unless the authorities take urgent action to prevent pitch invaders and he wants the FA to come down hard on Birmingham to act as a deterrent.

“It is absolutely disgusting and if we don’t stamp it out now, next time it could be a knife,” Shearer said in his column in The Sun.

“If that means docking them points, playing in an empty stadium, so be it. There cannot be a strong enough punishment. It’s completely ridiculous – I can’t remember seeing anything as blatant as this.”

Meanwhile, United defender Smalling took to Twitter on Monday morning to reflect on what happened during his side’s 2-0 defeat at Arsenal.

He said: “Commenting would only add to the attention he craved… Disappointed with yesterday’s result but we’ll learn from it. Looking ahead. Have a good start to the week everyone!”

Gary Cooper, 30, from Chertsey in Surrey, was charged by the Met Police on Monday with common assault and going on to the playing area.