Raising a baby girl isn't easy!

David Beckham, who welcomed his first daughter with wife Victoria in July, tells WSJ Magazine that baby Harper has taken a toll on his famous coif.

"I got my first gray a few years ago, and a couple more since we've had the little girl," the 36-year-old (also father to sons Brooklyn, 12, Romeo, 8, and Cruz, 6) reveals. "I definitely feel different than I did 10 years ago."

That's not the only sign of aging the soccer star has noticed. Beckham has endured knee trouble and a ruptured Achilles over the years, in addition to a slight stress fracture of his spine.

"It takes a while for the Achilles to warm up," he admits. "Once I've had my coffee, I'm good."

A professional soccer player since 1992, the sexy Brit hopes to play for his national team during the London Olympics in 2012. "I don't just want to be a coach or manager," Beckham tells WSJ Magazine. "I want to play."