Walsh said that Cowell "loves" fellow contestants James Arthur and Jahmene Douglas, but claimed that the X Factor USA judge did not mention Maloney when they recently spoke on the phone.
The Mirror quotes Walsh as saying: "I spoke to him this week and I know he loves James and Jahmene but I don't remember him talking about Chris, no."
The 60-year-old judge even went so far as to joke that he sometimes forgets the 34-year-old Liverpudlian contestant is still in the competition.
He added: "Chris, who is Chris? Oh he is still there, the Liverpool guy. He has got a nan there."
Walsh, whose final act Union J left the competition last weekend, added that he believes Maloney is "a good singer", but not "a star".
"He is like Tony Christie. He is a great singer but he is not Tom Jones," Walsh commented.
Maloney is going up against Arthur and Douglas in the X Factor final this weekend. The winner will be announced on Sunday (December 9).
Watch X Factor host Dermot O'Leary and Xtra Factor presenter Caroline Flack speak to Digital Spy and other reporters about Christopher Maloney below: