Radwanska, who launches her title defence as top seed at the Sydney International today, is one of the craftiest players on tour, unravelling her rivals more with touch and angles than all-out power.

But the world No 5 admits conquering powerhouses like Williams and the other three players above her - Australian Open champion Victoria Azarenka, Maria Sharapova and Li Na - requires more brute. That is why her support team is more a boys' club.

"I have couple [of] hitting partners - they're guys, so of course they're playing stronger than the girls," the Polish glamour girl said yesterday.

"So, of course, the practice always a little bit harder and you do much more in practice to be prepared good for the match.

"It's always what I'm trying to do, but every match is different story, especially different conditions and on the different surface."

Radwanska, who took Williams to three sets in the 2010 Wimbledon final, is the only one of the top five playing a tournament the week before the season's first grand slam.

"Well, the last two months I didn't play any matches," she said. "I played in Czech, the league like I'm playing every year, but matches are different than the practice."

The Sydney International is the 23-year-old's first sanctioned tournament since losing all three matches at the season-ending championships in straight sets. She put her sluggish end to 2013 down to physical and mental fatigue after a successful Asian swing in October. AAP