Kate Hudson and Cameron Diaz are at war over Alex Rodriguez.

Cameron’s new relationship with the baseball star has infuriated Kate, who was in a relationship with Alex from May to December last year. Hudson believes Diaz is simply trying to get her back for sleeping with Justin Timberlake just days after the pair split in early 2007.

“Kate thinks it’s payback pure and simple. Cameron was actually in a serious long-term relationship with Justin,” a source told Us Weekly magazine. “She thinks it’s a joke Kate would be mad. Kate is only upset because she hates being single.”

Now, the 31-year-old Oscar nominee has started getting personal. “Kate thinks Cameron is an aging actress struggling to remain sexy and relevant,” the source added.

Meanwhile, it’s been reported the New York Yankee has banned Cameron from coming to his games because he wants to keep things casual with her.

“He doesn’t want what happened to him and Kate to happen between him and Cameron. Kate was at every New York game and then some and even went to Alex’s game practice. Things got too clingy, too fast,” an insider stated.