Premier League: Thomas Tuchel admitted Chelsea paid the price for too many "individual mistakes" as Arthur Masuaku's fortuitous late winner gave West Ham United a shock 3-2 victory on Saturday.
Gareth Bale came on as a 72nd minute substitute with Tottenham leading 3-0, but suffered a debut to forget as the North London club capitulated in astonishing fashion.
The two-time champions are in Group D and will kick off their campaign against Iceland on June 16 at the Spartak Stadium.