Defending champion Paula Radcliffe's readiness to run the ING New York City Marathon on Sunday is the final piece in the big-race jigsaw, according to race director Mary Wittenberg.

The New York Road Runners chief executive will welcome back Britain's world record holder at the start line in Staten Island as Radcliffe finally gave the green light to her participation following a bout of tonsilitis, which caused her to miss the world half-marathon championships in Birmingham earlier this month, and a foot injury that forced her out of the Berlin World Championships in August.

Radcliffe, 35, is aiming to cross the finish line first in Manhattan's Central Park for the third year in a row and become the first person to win the event four times since American Bill Rogers in 1979.

Her success against a field which includes Russia's Ludmila Petrova, Kenya's Selina Kosgei, Japan's Yuri Kano, and Ethiopian duo Derartu Tule and Dire Tune would also come in the 40th running of the New York City marathon.

And the Briton's presence means a lot to the race director, whose organisation has named Radcliffe its marathoner of the decade for the 2000s.

"It's a big deal," Wittenberg said. "Several weeks ago when we inked the deal, it was only then that I said 'okay, we're ready to go, we're ready for this race to happen now, we've got everything we need'.

"We're absolutely delighted she's coming back. Paula's meant so much to this race in recent years it's hard to imagine a marathon without her.

"It's especially fitting for the 40th running. Paula brings drama and intrigue and excitement to the race and I'd probably put her right up there at the top of the list of the top things about the 2009 race."

Radcliffe, whose world record stands at two hours 15 minutes 25 seconds and has a best New York time of 2:23:09 set in 2007, is one of four British women in the professional field.

Michelle Ross-Cope, with a personal best of 2:36:02, Kim Fawke (2:39:22) and Catherine Wilding (2:49:07) complete the quartet, while Ireland's Jolene Williams is set to make her marathon debut having run 32 minutes 43.77 seconds for 10,000 metres.

The men's race will also see its 2008 champion return as Brazil's Marilson Gomes dos Santos goes to the line in search of a third victory overall.

He will be up against an elite field also containing fellow two-time winner Martin Lel of Kenya, 2004 champion Hendrick Ramaala of South Africa and Olympic silver medallist Jaouad Gharib of Morocco.

Kenyan duo James Kwambai, with a personal best of 2:04:37, and Patrick Makau, who ran 2:06:14 for fourth place in Rotterdam earlier this year on his marathon debut, will also pose a threat to the Brazilian's title defence.

The men's race also doubles as the American national championship and the home contingent will be led by Ryan Hall, 10th in the Beijing Olympic marathon, whose personal best of 2:06:17 was set in London in 2008 when finishing sixth.