Shearer said Kinnear's appointment had left the Toon looking "a laughing stock".
"What Shearer says is diabolical," said Kinnear to the Sunday Times. "This is a guy who hasn't got a clue about coaching."
He added: "The last game of the (2008-09) season he came up with the master idea of playing Damien Duff at left-back. Damien is one of the best left-wingers in the business, but can't tackle. And we went down with an own goal from Damien.
"Shearer keeps slagging me off. He is being disrespectful to me. I am entitled to fight back."