By Ian Ransom

MELBOURNE (Reuters) - Former world number one Lleyton Hewitt is likely to drag his injured foot into Australia's Davis Cup playoff tie against Switzerland next month in the hope of helping his country secure a place in the elite World Group.

Hewitt pulled out of the U.S. Open on Tuesday after suffering a painful second-round exit from the Winston-Salem Open in North Carolina.

Australia has lost all three of its World Group play-offs in the past three years and faces a Herculean task to beat a Switzerland team potentially loaded with the likes of Roger Federer and 14th-ranked Stanislas Wawrinka.

Hewitt's manager David Drysdale told Reuters the 30-year-old needed to rest an injured toe that had plagued him for most of the season but had nonetheless committed to the September 16-18 tie at the Royal Sydney Golf Club.

"I'd be highly surprised if he didn't play," Drysdale said in a telephone call. "Apparently, the grass courts won't be as much of a strain on the injury.

"He'll come home in about a week and we'll re-assess then."

Hopes of a Davis Cup revival have been sparked at home, however, with the emergence of talented teenager Bernard Tomic, whose surprise run to the quarter-finals at Wimbledon dethroned Hewitt as Australia's number one.

Hewitt played a decisive role in carrying Australia to the Switzerland play-off, playing through pain to win his reverse singles rubber in the second round tie against China in July.

The 2001 U.S. Open champion and 2002 Wimbledon champion has since slipped to 188th in the world rankings -- his lowest in more than a decade -- as he suffered a succession of injury setbacks in his keenness to continue to figure at grand slams.

(Editing by Greg Stutchbury)