London - Defending champion Novak Djokovic and six-time winner Roger Federer were once again set on a Grand Slam collision course when they were placed in the same half of the Wimbledon draw on Friday.
World number one Djokovic, who swept past Federer in straight sets in the French Open semi-finals earlier this month, could meet the Swiss again in the last four.
The top-seeded Serb will start his campaign against Spain's former world number one Juan Carlos Ferrero while Federer, who has lost in the quarter-finals in the last two years, takes on another Spaniard, Albert Ramos.
Second seed Rafael Nadal, the 2008 and 2010 champion, and fresh from a record seventh French Open title, meets Brazil's Thomaz Bellucci.
Fourth-seeded Briton Andy Murray, who has lost in the semi-finals in the last two years to Nadal, is scheduled to meet the Spaniard again in the last four, but first he must get past wily Russian Nikolay Davydenko in his opener.
Lleyton Hewitt, the 2002 champion, begins against French star Jo-Wilfried Tsonga, who knocked out Federer in five sets in the quarter-finals last year.
Hewitt's Australian compatriot Bernard Tomic starts against Belgium's David Goffin who went through qualifying at the French Open and reached the fourth round where he took a set off Federer before losing in four.
In the women's draw, top seed Maria Sharapova, the 2004 champion and this year's French Open winner, begins against Australia's Russian-born Anastasia Rodionova.
Unseeded Kim Clijsters, a four-time Grand Slam title winner who will retire after the US Open, is in the same quarter of the draw as the Russian and begins against fellow former world number one Jelena Jankovic.
China's number one Li Na, beaten in the second round by Sabine Lisicki 12 months ago, tackles Russia's Ksenia Pervak in the first round.
Defending champion Petra Kvitova of the Czech Republic, the fourth seed, starts her campaign against Akgul Amanmuradova of Uzbekistan.
Five-time champion Venus Williams, unseeded this year, takes on Russia's Elena Vesnina while sister Serena, a four-time winner, faces Barbora Zahlavova Strycova of the Czech Republic.
Second seeded Victoria Azarenka, the Australian Open champion, could face Kvitova in the semi-finals, but first the Belarussian takes on America's Irina Falconi.