Sheffield United manager Paul Heckingbottom says football is the "worst sport" for racism, calling for tougher punishments to stamp out abuse.

United goalkeeper Wes Foderingham took to Instagram to reveal he had suffered from "racism and family threats" after last week's 2-1 defeat at Tottenham.

Heckingbottom revealed police have spoken to the former Rangers keeper about the incident, which he said reflected a larger problem in society.

"You can say it's all social media and people are tough on there and they can say what they want," he said on Friday. "You can take it away, but it is deeper than that because it's inside people."

He added: "It's sad -- I think we are the worst sport for it. I don't know if it's the profile but we are the ones who get the most.

"There have been big improvements, in society and our game, so we have to just continue being harder and stronger and every time we get a prosecution let's make those punishments harder."

The Blades take on Newcastle on Sunday aiming for their first victory of the season.

They were minutes away from winning at Tottenham last week before conceding two goals deep into stoppage time.