The Republic of Ireland international has been subjected to sick messages on Instagram in recent months including sectarian slurs, death threats, and taunts about his late father.
Duffy, 29, was targeted again earlier this week, receiving messages from a user with Rangers player Ianis Hagi as their profile photo saying: “Hope you die in your sleep, your s****” accompanied by a Union Jack flag emoji and the number 55.
In a second message, the user wrote: “Ahaha your da died ya c***.”
Duffy shared the messages with his 105,000 followers with the caption: “Thanks Instagram”.
Now his mother Siobhan has taken aim at the trolls abusing her son.
Writing on social media she said: “What is wrong with people! This is my son, who is dealing with the loss of his best friend and father.
"How dare they. There is limits. It’s a game of football. Get a grip.
"Something needs to be done about these trolls – as if mental health isn’t bad enough. So much for #bekind.”
Instagram has since confirmed that the account has been removed for violating company guidelines, but a previous user was allowed to keep their account after deleting their messages and apologising to the player, with the social media giant viewing it as an isolated incident.