The Blade: Trinity star, who is dating pop star Justin Timberlake, admits she's intrigued by the married mother-of-two, her glamorous looks and envious film career.
However, 27-year-old Biel insists she's no competition for Affleck, because her admiration for Garner is purely platonic.
She explains, "My girl crush is Jen Garner at the moment (but) here's the thing with girl crushes: it's more of a respect thing. It's like, you're beautiful, you're cool, you look and seem like somebody I would want to hang out with and your career is awesome."