Roger Federer and Rafael Nadal
Roger Federer beat Rafael Nadal in the final of the Shanghai Masters last month

The draw for the season-ending 2017 London ATP World Tour Finals suffered a nightmare of almost Carabao Cup-esque proportions on Wednesday morning (8 November), with top seeds Rafael Nadal and Roger Federer forced to wait to discover their fate.

Initially due to be conducted at 08.15 GMT on BBC Radio 2's flagship Breakfast Show with Chris Evans, proceedings were eventually delayed by around 45 minutes due to Boris Becker - after whom Group B in the singles competition has been named this year as the Finals Club continue their initiative to celebrate past champions - being caught in heavy traffic en route to the studio.

When Becker arrived and the round-robin draw finally did get underway, reigning men's world number one Nadal, who is expected to play in the tournament despite pulling out of the Paris Masters quarter-finals with a lingering knee injury, was placed in Group A - which this time bears the name of five-time winner Pete Sampras - alongside fourth-ranked Dominic Thiem and debutants Grigor Dimitrov and David Goffin.

Federer, meanwhile, landed in the Becker group with two more first-time competitors in talented German youngster Alexander Zverev and unseeded Paris winner Jack Sock.

He will also once again come up against Marin Cilic, the former US Open winner he beat in straight sets in July to seal a record eighth Wimbledon singles title.

2016 finalists Andy Murray and Novak Djokovic will miss this year's finals due to injury and have both now dropped out of the world's top 10. Qualifier Stan Wawrinka also saw his season ended prematurely by a knee problem, paving the way for American Sock to participate. The likes of Milos Raonic and Kei Nishikori are also absent.

The ATP Finals begin at London's O2 Arena on Sunday (12 November). The top seeds from each group progress through to the semi-finals, where they then go head-to-head with the runner-up from the corresponding group. The final two players remaining will square off in the final on 19 November.

In the doubles draw, Jamie Murray and Bruno Soares were paired in Group Woodbridge/Woodforde with a duo that are seeking to end the year ahead of defending champions Henri Kontinen and John Peers atop of the world rankings in Lukasz Kubot and Marcelo Melo.

ATP World Tour Finals draw in full:

Singles

Group Pete Sampras

Rafael Nadal, Dominic Thiem, Grigor Dimitrov, David Goffin

Group Boris Becker

Roger Federer, Alexander Zverev, Marin Cilic, Jack Sock

Doubles

Group Woodbridge/Woodforde

Lukasz Kubot/Marcelo Melo
Jamie Murray /Bruno Soares
Bob Bryan/Mike Bryan
Ivan Dodig/Marcel Granollers

Group Eltingh/Haarhuis

Henri Kontinen/John Peers
Jean-Julien Rojer/Horia Tecau
Pierre-Hugues Herbert/Nicolas Mahut
Ryan Harrison/Michael Venu