Bukayo Saka Marcus Rashford and Jadon Sancho were all targeted by abusive posts in the wake of their missed penalties in the shoot-out.
Figures within the sport, from the Government and even the Duke of Cambridge were united in their condemnation for the abuse, and Southgate said: “For some of them to be abused is unforgivable really.
“I know a lot of that has come from abroad, that people who track those things have been able to explain that, but not all of it.
“It’s just not what we stand for. We have been a beacon of light in bringing people together in people being able to relate to the national team, and the national team stands for everybody and so that togetherness has to continue.
“We have shown the power our country has when it does come together and has that energy and positivity together.
“We heal together as a team now, and we’re there for them, and I know that 99 per cent of the public will be as well.
“Bukayo in particular has been an absolute star in this tournament, (he has shown) incredible maturity and the way he has played has brought a smile to so many people’s faces. He’s become such a popular member of the group and I know he has got everybody’s support.”
Arsenal released a statement stating their pride in how Saka had represented his club and his country during the tournament, which had turned to sorrow when witnessing the abuse the 19-year-old suffered.
“We are sad to have to say we condemn the racism of a number of black players,” the statement read. “This cannot continue and the social media platforms and authorities must act to ensure this disgusting abuse to which our players are subjected on a daily basis stops now.”
Manchester United compiled messages of support for striker Rashford on their website, and a statement introducing the posts said: “It takes tremendous guts to take a penalty under such pressure, when the entire nation is anxiously watching on, so we are proud that Marcus was brave enough to step up.”
The Duke of Cambridge, who is president of the Football Association, said he was “sickened” by the abuse. “It is totally unacceptable that players have to endure this abhorrent behaviour,” he wrote on Twitter. “It must stop now and all those involved should be held accountable.”