An EFL spokesman said: "The EFL condemns the mindless actions of the individual who encroached on to the pitch at St. Andrews on Sunday afternoon".
"The guy who ran on the pitch has gone there to cause havoc, not watch the football".
"Because the more satisfied you are with your personal life, the less you need to do this kind of act".
"It's that serious. Where are we at in football when some thug thinks that is what he is going to do?"
"It needs to be top-end stuff, the players need protecting more than anything else".
"Drastic action is needed - either through points deductions or by emptying stadiums and making clubs play behind closed doors".
Grealish said the ugly incident, which led to an individual being arrested by West Midlands Police, took him by surprise, but did not overshadow a proud day.
Prosecutor Jonathan Purser told the court that Grealish felt lasting pain after the incident but had suffered no substantial injury from a punch to the right side of his jaw.
Metropolitan Police said a man was in custody on Sunday night after being arrested over the incident.
"We trust the perpetrator will feel the full force of the law and the authorities investigate the circumstances surrounding today's deplorable incident", the club said in a statement.
Mitchell's solicitor, Vaughn Whistance, said during the court proceedings that his client "cannot explain what came over him yesterday morning".
"There have been various comments posted on different social media platforms", he said.
Grealish and Aston Villa ended up having the last laugh though as he ended up scoring the game-winning goal in just the 67th minute. There can not be a strong enough punishment.
The shocking scenes left the football world stunned. It was unbelievable, in front of our fans and after what happened in the first half. "Imagine Jack's family sitting at the side and thinking about what could possibly have happened". "Looking ahead. Have a good start to the week everyone!"