"I don't like reading negative things about Clint," the 48-year-old wrote Monday. "He is a wonderful, good natured, brilliant person. No matter what, I attest to that."
Dina, who starred in a short-lived 2012 reality show about her life, announced last week that she and Clint, her husband of 17 years, had been living separately "for some time."
While a source told US Weekly that the split had been "amicable," the "Million Dollar Baby" star's manager only said "I know nothing about that."
Clint, meanwhile, was seen dropping off a "mystery woman" at LAX over the weekend. Sources told E! News that the unidentified blonde spent the night at his L.A. home before leaving town.