The 30-year-old has been linked with a transfer away from Stamford Bridge this summer although the Blues claim his absence from the trip is due to the need to recover from a knee injury.
Drogba's omission seems certain to raise further questions about his future with a virtually full-strength squad travelling to play games in China and Malaysia and Russia.
Another player rumoured to be on his way from the Londoners, Inter Milan target Frank Lampard, is included in the party.