Southgate did not name anyone in his press conference this afternoon, but he and victim Paul Stewart were briefly teammates at Crystal Palace in the mid-1990s
The new England manager has revealed one of the footballers who has claimed he was sexually abused as a young player was a teammate.
Speaking following his appointment, Gareth Southgate told a news conference: "I played with one of the players who has recently come forward.
"The reality of that, as they have said, is that they haven't felt able to speak about that until this moment, and that's completely understandable.
"And of course with the benefit of hindsight you always relay then things that you have seen from the past and have an understanding, 'oh, okay, that's why we saw the things we saw'."
He did not identify the player, but he and victim Paul Stewart were briefly teammates at Crystal Palace in the mid-1990s - long after the abuse took place.
"The situation we have now in terms of child protection is completely different, but we mustn't be complacent and think that we have got everything right," Southgate said.
"I think that we are in a much better place than we were 15 to 20 years ago."
Former Crewe Alexandra player Andy Woodward was the first ex-player to reveal he had been abused, prompting an investigation by the Football Association.
A series of other former footballers have also since waived their anonymity to speak publicly about their experiences of sexual assault in youth football.
Southgate described the bravery of those who have spoken out as "exceptional", adding: "To hear the stories is heartbreaking."
Fourteen police forces across the UK are now investigating claims of historical child sex abuse in the sport.
Around 350 victims have come forward, the National Police Chiefs' Council revealed on Thursday, with the NSPCC adding that a dedicated hotline set up in response to the allegations received 860 calls in its first week,
Asked if claims some clubs have paid "hush money" to victims would be investigated, FA chief executive Martin Glenn replied: "If there has been any evidence of any breach of the rules - including hushing up - we will, absolutely will, from top to bottom regardless of size of club."
He said "child abuse is a society issue", but "if the FA have made errors, we will own up to them".
"It needs to be dealt with because there are some clearly damaged people whose bravery we should acknowledge in actually coming out because it will help uncover some issues that we can't let go forward," Mr Glenn added.
The FA has commissioned an internal review into what actions it took in the past and the conduct of clubs where abuse may have taken place.
If you have been affected by any of the issues in this article, you can contact 'One in Four', a charity providing support and resources for people who have experienced sexual abuse and violence in Ireland.