Top-seeded Roger Federer will try to win his seventh title at the Swiss Indoors starting on Monday.
The 34-year-old Swiss world number three, who won his sixth Swiss title last year, will start his title defence on Tuesday against Mikhail Kukushkin of Kazakhstan.
In a chat with media ahead of the tournament, Federer said he was happy to be back at the age of 34 to play in his hometown event.
"Ten years ago I would have only hoped to be still able to play at 34, yet here I am.
“I'm going through a really exciting phase of my career, of my life. I can only be happy," said Federer.
Other big names participating in the event are Swiss countryman Stan Wawrinka, seeded second, and third seed Rafael Nadal of Spain.
Wawrinka will be up against Croatian Ivo Karlovic while Nadal kicks off the week's evening sessions when he faces Lukas Rosol on Monday.
Big serving South African Kevin Anderson is seeded fourth ahead of Frenchman Richard Gasquet and America’s John Isner, who is the sixth seed.
Marin Cilic is seeded seventh ahead of David Goffin.
There were two injury pullouts when the tournament lost big names Kei Nishikori of Japan and Canadian Milos Raonic.