Danny Drinkwater made his first competitive appearance in a Chelsea shirt since August 2018 as their under-21 side lost 4-3 at Bristol Rovers in the Papa John’s Trophy.
The Londoners, whose starting midfield also included 19-year-old Scotland youth international Billy Gilmour, were beaten by Josh Hare’s 90th-minute goal.
Wednesday’s other game saw Morecambe enjoy a 4-0 win over Manchester United.
Harvey Neville, son of England Women head coach Phil, was in United’s team.
The 18-year-old followed in the footsteps of his father Phil and uncle Gary Neville in playing at full-back.
The young United side had already qualified for the knockout stages, while Morecambe were already eliminated.
Bristol Rovers’ late win sent them through, while Chelsea go out.
The draw for the second round will be made on Friday, 20 November.