The Professional Footballers' Association believes there is "still much work to do" to educate players following Adam Johnson's conviction for child sex offences.
The ex-Sunderland forward, 28, is facing jail after being found guilty of sexual activity with a girl aged 15.
The PFA runs programmes to teach players about "personal integrity".
And it said it was "extremely disappointed" to see the damage that had been caused by one of its members.
"As the players' union, we are very conscious of the role and responsibility of our members and we work hard to ensure they receive relevant information and important guidance regarding appropriate standards of conduct," the organisation said in a statement.
"Situations such as this, unfortunately, demonstrate that this is a vital area for our focus and that there is still much work to do."
The players' union said its training programmes incorporate "the theme of personal integrity for all professional players, ensuring they are fully informed on such issues and includes sexual consent, standards of behaviour and respectful relationships in person and on social media".
'A massive shock'
Former England international Johnson had denied all four charges he faced up until the start of his trial last month.
After admitting to two charges on the first day of his trial - one of grooming and one of sexual activity - he was found guilty on Wednesday of sexual touching, but not guilty on a charge relating to another sexual act.
He had been playing for Sunderland until the start of his trial but was sacked after admitting to the two charges.
Black Cats manager Sam Allardyce said Johnson's change in plea had come as a "massive shock", adding: "I was sat at home when it came on the news and I just was gobsmacked.
"As far as we were concerned, it was his intention to plead not guilty on all charges. That is why we continued to let him train and play for us.
"Now the judgement has been made, we all feel extremely let down by what has happened and by what Adam has done and certainly feel a lot of sympathy for the victim and the family."
The trial at Bradford Crown Court heard evidence that the club's chief executive, Margaret Byrne, met Johnson and his barrister in May 2015, when he accepted he had kissed the girl and exchanged messages with her.
The jury was told that, before the case came to court, club bosses had seen all the 834 WhatsApp messages the pair sent to each other, along with transcripts of police interviews.
'Questions just not answered'
On Wednesday, Sunderland issued a statement denying they "knew all along that Mr Johnson was intending to change his plea just before trial to enable him to continue to play football for the club".
But Clare Phillipson, director of charity Wearside Women in Need, said: "I think there are questions that are just not answered in that statement, around what Johnson said in court, about what they knew and when."
The Football Association said it spoke to the club in April 2015 to confirm that "Johnson did not have any roles with the club involving a position of trust with children and was not involved in their community schemes".
In a statement issued on Thursday, it added: "Adam Johnson's conduct in this case is to be condemned. Our thoughts are with the victim and her family as they look to rebuild their lives after this traumatic ordeal."