Six-time champion Roger Federer has been paired in the same group as German debutant Alexander Zverev for next week's ATP Tour Finals in London.
World No.1 Rafael Nadal, who is hoping to recover from a knee injury to play in the season-ending showpiece, heads the other group and will face Belgian David Goffin, Bulgarian debutant Grigor Dimitrov and Austrian Dominic Thiem.
Also in the Pete Sampras group with Federer is Croatian Marin Cilic, the man he beat in this year's Wimbledon final, and American Jack Sock who crept into the tournament after winning the Paris Masters.
Zverev, 20, has taken men's tennis by storm this year, rocketing up to No.3 in the world rankings after winning five titles, including two Masters 1000 events.
"It's an honour to play there in London, it's my first time and hopefully not my last," Zverev said in Milan, where he took part in an exhibition match at the Next Gen Finals, having dropped out to concentrate on London.
"I will try to prepare myself as well as I can and try to win many matches there."
He is one of three first-timers with Dimitrov finally qualifying after being long-predicted to become a regular member of the men's elite. Sock is the first American to qualify since Mardy Fish did so in 2011.
Several high-profile players are missing this year through injury including 2016 winner Andy Murray, four-time London winner Novak Djokovic and Stan Wawrinka.
THE DRAW (world ranking in parentheses):
Pete Sampras Group:
Roger Federer - Switzerland (2)
Alexander Zverev - Germany (3)
Marin Cilic - Croatia (5)
Jack Sock - US (9)
Boris Becker Group:
Rafael Nadal - Spain (1)
Dominic Thiem - Austria (4)
Grigor Dimitrov - Bulgaria (6)
David Goffin - Belgium (8)
