Gerrard thinks that the 32-year-old, who was released by the Red Devils at the end of last season after three years at Old Trafford, has lost his "legendary status" at Anfield since making the move.
"I'm very rarely in touch with Michael Owen these days," Gerrard said in his new book Steven Gerrard: My Liverpool Story. "I have to be honest and say I was very surprised he chose to sign for Manchester United.
"Michael enjoyed legendary status at Liverpool but that has been diluted because of the move he made. Only Michael knows if he got that decision right."
Owen, who came through Liverpool's academy along with Gerrard, joined Stoke City at the start of the season.