Isaiah Crowell, 23, has already apologized for posting a viral ISIS-style picture of a man in black slitting the throat of a white cop on Instagram, but it's not enough for his team - or local police.

The Cleveland Browns released a statement scolding the NFL player Tuesday for his 'disturbing and unacceptable' post and said his apology was 'not enough'.

But the team's anger pales in comparison to the fury of Stephen Loomis, President of Cleveland Police Patrolmen's Association, who told TMZ he would 'pull (cops) out of FirstEnergy Stadium if (Crowell) doesn't make this right.'

Scroll down for video

NFL star Isaiah Crowell posted an image (pictured) of a man slitting the throat of a white cop on June 6, just before the Dallas shooting. Cleveland cops are now threatening to pull protection for the team's stadium

The running back has since apologized and deleted the picture, claiming he'd been angry and 'emotional' over the deaths of two black men killed by police officers last week, but both cops and his team say it's not enough

In a statement released Tuesday, the team said: 'We have spoken to Isaiah regarding his extremely disturbing and unacceptable social media decision.

'It was completely inappropriate and we have made him aware of our high level of disappointment.

'Isaiah has apologized but also knows that just an apology is insufficient and that he must take steps to make a positive difference after a very negative and impactful post.'

Their demands for Crowell were echoed - in even angrier tones - by Loomis, who is demanding the club come down hard on the player, or face his wrath.

'(Crowell) needs to go to Dallas, help the families who lost their loved ones last week, write them a check, look them in the eyes and give a heartfelt apology,' Loomis told TMZ.

He said that Crowell's post was as 'offensive as putting a picture of historical African-American men being hung from a tree in the 60s' and that Crowell's apology - in which the player said he was 'emotional' because of the recent killing of two black men by police - was 'store-bought.'

'You're a grown-a** man, and you claim you were too emotional to know it was wrong? Think we'll accept your apology? Kiss my a**.'

He also warned: 'I will pull Cleveland officers, sheriffs, state troopers out of FirstEnergy Stadium this season if he doesn't make it right.'

Stephen Loomis, President of Cleveland Police Patrolmen's Association says he will pull police protection from the Cleveland Browns stadium if Crowell doesn't 'make it right' (picture courtesy WEWS)

The NFL also commented, with spokesman Brian McCarthy telling Cleveland.com: 'The image was inappropriate and insensitive. He realized this, took down the post and has since apologized.'

Crowell, who is in his third year with the Browns, had posted the shocking image on Instagram with the caption: 'Mood: They give polices all types of weapons and they continuously choose to kill us #Weak.'

He subsequently apologized and deleted the picture, claiming he'd been angry and 'emotional' over the deaths of two black men killed by police officers last week.

The picture first appeared online on June 6 after Philando Castile in Falcon Heights, Minnesota, and Alton Sterling in Baton Rouge, Louisiana, were fatally shot by cops, CBS reports.

Less than 24 hours later, gunman Micah Johnson opened fire at a peaceful Black Lives Matter protest, killing five officers and injuring seven more.

Crowell, who signed a $1,540,000, three-year contract with the Browns in 2014, posted a statement apologizing for his Instagram post on Monday.

'Last week was an emotional and difficult week as we saw extreme acts of violence against black men across our country as well as against police officers in Dallas,' he wrote.

'I posted an image to Instagram in the midst of that emotion that I shouldn't have and immediately removed it.

'It was an extremely poor decision and I apologize for that mistake and for offending people. My values and beliefs do not match that image.

The running back explained he had been 'outraged and upset' by the deaths of Alton Sterling and Philando Castile.

But he said he was also 'outraged and upset' over the Dallas shooting of five cops.

'I was very wrong in posting that image,' he continued. 'Every single life matters, every death as a result of violence should be treated with equal outrage and penalty.'

The picture mimics the beheading of journalist James Foley by ISIS terrorist known as Jihadi John in 2014

Despite his apology, many people on social media were furious and have called for the Cleveland Browns to drop Crowell over his offensive post.

It is not yet known if the team or the NFL plan to take action against the player.

The image shows a cartoon drawing of a white cop kneeling on the ground in front of a man, dressed entirely in black except for two gun straps in the colors of the American flag and an Ankh necklace - a popular symbol of black culture.

Blood can be seen spurting out of the officer's neck as the man in black slits his throat.

In one version of the image, which has been shared thousands of times on social media, it adds a caption which reads 'As a R.B.G killer panther, I pledge to defend my black community by any means necessary.'

The picture mimics videos by terrorist group ISIS, showing the extremists beheading American and British victims.

The running back explained he had been 'outraged and upset' by the deaths of Alton Sterling and Philando Castile. But he said he was also 'outraged and upset' over the Dallas shooting of five cops

'The cartoon image is a clear rendering of the Islamic State's execution by Jihad John of journalist James Foley in 2014 - even down to the gun strap Jihadi John wore, which is recreated in the image of the US flag,' Veryan Khan, editorial director of the U.S.-based Terrorism Research & Analysis Consortium, told Fox News.

'Ironically, the Islamic State has picked up on the propaganda material and is now using the same image on its social media pages, including on the media site Telegram.'

Terrorism experts are investigating whether the originator of the image has links to extremism.

The CEO of the National Sheriffs' Association, Jonathan Thompson, branded the image 'disgusting and dehumanizing to law enforcement' as he warned that it encouraged violence.

'Whether it is depicting a journalist, teacher or cop being beheaded, this has no place in our society.'

The picture was first posted to Facebook on June 6 and shared around 8,000 times, Fox News reports.

It was often accompanied by hashtags such as #blacklivesmatter or #killpigs.

Several users claim that they reported the picture to the social media giant who allegedly took no action.

But by Monday, Facebook released a statement saying they would remove the picture, along with any other posts promoting or glorifying violence.