Gianfranco Zola believes there is little prospect of social media platforms becoming safe spaces for sports stars, warning: "Bad people will always be there."
England footballers Bukayo Saka, Marcus Rashford and Jadon Sancho were subjected to racist abuse online after their penalty shoot-out misses in the Euro 2020 final.
Those failures from the spot helped Italy to land their second European Championship triumph.
There have been calls for the likes of Twitter, Instagram and Facebook to police their platforms more effectively, with 19-year-old Saka urging the three tech giants to each step up their game.
Former Italy and Chelsea forward Zola told Stats Perform: "Racial abuse is unjustifiable, unforgivable and unacceptable. I reckon that youngsters have to understand very quick that not all people they come across on social media are good.
"They use it to provoke, insult, abuse and vent their daily frustrations. We have to get used to it and learn how to isolate from this. Especially young people who are famous like footballers.
"These are all unjustifiable attacks but we have to learn how to isolate from it all because these bad people will always be there."
Zola, who enjoyed a seven-year spell at Chelsea and collected 35 caps for the Azzurri, explained there is a "dark side of social media".
He said: "Many people use [social media] in an absurd way and can cause damage to kids who are on social media and are not ready to accept all this.
"If you are into social media, you have to be aware these can be used by people to insult and destabilise. This is the dark side."