France defender, William Saliba, was picked by UEFA for a post-game anti-doping control on Tuesday.
Saliba played all 90 minutes as Les Bleus were held to a 1-1 draw by Poland in their final group fixture.
The result saw Didier Dechamps’ men qualify for the Round of 16 as runners-up in Group B.
However, according to L’Equipe, Saliba was left behind at the Signal Iduna Park in Dortmund.
The rest of the squad left with the team bus as the testing took longer than expected.
Saliba has played in all three games so far and kept two clean sheets, before a Robert Lewandowski penalty breached their defence.