The Portuguese coach called on Lukaku last week to reveal the reasons behind his decision to leave Chelsea for the Toffees on a season-long loan.
Despite Mourinho's public claims, Barry has insisted that Lukaku, who moved to Goodison Park on transfer deadline day in the summer, has not been affected by them.
"He didn't let it distract him," the Liverpool Echo quotes Barry as saying. "The lads spoke to him about the headlines and gave him a bit of stick about it.
"Rom is very strong-minded and confident in his own ability. He can keep concentrating and hopefully keep scoring goals."
Lukaku added to his goal tally in Saturday's 4-0 win over Stoke City.