Cameron Diaz can't compare to Alex Rodriguez's ex Kate Hudson -- if you ask the New York Yankees player's kids, that is.

A source close to A-Rod tells the new issue of Us Weekly (on stands now) that Natasha, 6, and Ella, 2, "liked Kate more than Cameron, since she had Ryder [Hudson's 6-year-old son]. They really miss him."

For her part, Diaz, 38, did her best to impress the girls while vacationing in Cabo San Lucas, Mexico over the holidays. The Green Hornet actress "hung out with the kids all day, splashing in the pol and playing tag," a witness tells Us.

Find out more about what A-Rod's kids think of Diaz in this week's Hot Stuff video, as explained by Senior Editor Ian Drew.

Also in the roundup: Courteney Cox is "pissed" she didn't get a Golden Globe nod for Cougar Town, Ryan Phillippe and Amanda Seyfried's relationship heats up, and much more!