Coleen took to Twitter to respond to a user, who was mocking the 27-year-old for undergoing a second reported £15,000 procedure following his initial op in 2011.
Following the transplant, Rooney was spotted without his usual crop of hair, prompting a Twitter user to write: "What's going on with @Wayne- Rooney hair transplant what a waste of money!"
Coleen responded: "That's what happens!! It falls out before it grows back!!"
Meanwhile, United manager David Moyes has insisted that Rooney will not be sold this summer.