But Shearer told BBC 5 Live: "I'm sure what he said in his autobiography will be brought up but they're grown adults.
"They'll get over that, it won't be a problem at all I promise you."
Shearer, who was signed by Keegan in 1996 for a club record £15m, said that Owen would be allowed to flourish under the new Magpies manager.
"Any centre forward playing under Kevin Keegan will love it," Shearer said.
"He wants to attack, he wants to play with two wingers who will get the ball in the box as often as possible.
"And if that's the case then Michael Owen will certainly enjoy playing under him because he will score goals as he has done wherever he has been."