(CNN) -- Roger Federer will face U.S. Open champion Juan Martin Del Potro, home hope Andy Murray and Spain's Fernando Verdasco in the tougher of the two round robin groups for the ATP World Tour finals in London next week.
The other group consists of world number two Rafael Nadal, defending champion Novak Djokovic, Russian Nikolay Davydenko and Robin Soderling of Sweden.
Soderling gets his chance in the elite end-of-season showpiece because of injury to American Andy Roddick with Jo-Wilfried Tsonga of France moving up to first reserve in the event of further injuries during the tournament.
Four-time champion Federer will be looking to revenge his defeat in the U.S. Open final to Argentina's Del Potro while world number four Murray will also provide stiff opposition when the touranment starts at the O2 Arena on Sunday.
Murray, who was at Wednesday's draw, acknowledged that the group will offer a considerable challenge.
"Whoever you draw is going to be tough," he told www.atpworldtour.com.
"Obviously I look forward to playing Roger. I've played Juan a few times on the tour recently and also had a close match recently with Verdasco indoors in Valencia. It's a tough group but if I play well I think I have a good chance of qualifying."
Djokovic goes into the finals as the in-form player, having won last week's Paris Masters title, brushing aside Nadal in straight sets on the way to the final.
The week before he beat Federer on his home court in Basel to win the final of the Swiss Indoors.
The top two players in each of the round robin groups advance to the semifinals of the tournament, with a possible $1.63 million on offer to a champion who is also undefeated in group stages.
Federer, who took over as world number one in mid-season as Nadal was sidelined by injury, could still lose the No.1 ranking to the Spaniard.
An undefeated winner of the tournament will claim 1,500 points in the rankings with the Swiss star's lead over Nadal at 945 points.
The world's top eight doubles pairings are also competing in their finals.