Everton manager David Moyes saw his young pretenders tumble to a narrow 1-0 defeat to BATE Borisov.
The Toffees were in action in Europa League Group I at Goodison Park, having already qualified for the knockout phase.
The experimental XI sent out by the Scot held on until the 75th minute when a goal from Aleksandr Yurevich won the match for BATE Borisov.
Of more concern to Moyes was an injury to Jack Rodwell, which saw the midfielder come off after eight minutes.
injury list
Moyes already has a lengthy injury list which contains the likes of Phil Jagielka, Mikel Arteta and Phil Neville.
He can ill afford the talented Rodwell to be out for long, with so many players on the sidelines.
Jake Bidwell - at 16 years and 271 days - became the youngest player to figure for the Toffees in Europe and the third youngest behind Jose Baxter and James Vaughan to play for them overall.
Baxter, Shane Duffy and Seamus Coleman were among the youngsters to turn out for the Toffees.
The draw for the Europa League last-32 is on Friday.