The Leeds owner wouldn't specify who that someone was, however...
Indeed, Child resigned from his senior role at Leeds last season despite being a life-long fan of the club, as reported by the Yorkshire Evening Post at the time.
And Cellino says his departure was caused by a breakdown in relationship with one of his colleagues - but wouldn't name who.
The Italian told Sky Sports News: "I don't think people left because of the way I work. Matt Child left because he didn't get along with someone else who was working in the club.
"I think Matt Child was not really a football man. He was a good professional but not really a football specialist. The one that was specialised for this job was Adam Pearson and I don't think he left from my way."
It seems the chaos of last season will never be fully revealed. Maybe if someone writes an autobiography one day...
But the past, even if it is still fresh in the memory, has now gone and Leeds fans can at least hope their current stability will last.
Interestingly, Cellino admits he could still end up reverting to his old ways in terms of sacking managers but says he likes working with Uwe Rosler because he's professional. Whether that's a comment on previous coaches, who knows?
Pearson's exit, meanwhile, will no doubt hurt Leeds but they have this week signed Will Buckley, showing that life at United can go on as normal without him.