The actress and the Yankee are said to have ended their seven-month relationship.
An onlooker at a Miami restaurant said “He flirted with a blonde all night at dinner and seemed very much single.”
Representatives for the couple are yet to comment, but a source said: “They are totally over.”
Kate was asked by ‘Late Show’ host David Letterman, if she was a big Yankees fan and friends with Alex, to which she giggled and said: “Yeah, he’s a friend of mine. Nice guy.”