World number one and defending champion Roger Federer [ Images ] of Switzerland [ Images ] was grouped with Australia's [ Images ] Lleyton Hewitt [ Images ] in the draw on Wednesday for the season-ending ATP Tennis Masters Cup.

Federer, the winner of three Grand Slams this season, and Hewitt will be joined the Red Group by Spain's Carlos Moya [ Images ] and Argentina's Gaston Gaudio.

Topping the Blue Group will be world number two Andy Roddick [ Images ] of the United States, with in-form Russian Marat Safin [ Images ], Britain's Tim Henman [ Images ] and Argentina's Guillermo Coria completing the elite eight-player field.

Play in the $4.5 million tournament begins on Monday with the top two in each group advancing to the semi-finals.

Federer has not played since injuring his thigh preparing for his home tournament in Basel last month and he will be relieved to have avoided Henman, who holds a 6-3 record over the Swiss in head-to-head meetings.