Chijindu Ujah's place at next month's European Championships in Switzerland looks in doubt after he finished sixth at Saturday's Diamond League meeting.
The Enfield and Haringey Athletics Club sprinter was making his Diamond League debut in Paris but could only manage a disappointing time of 10.20.
Michael Rodgers won the event with a wind-affected time of 10.00; Richard Thompson coming second and Kim Collins in third.
Ujah, 20, became only the fifth Briton to a run a sub-ten second time in the 100m when he clocked 9.96 in the Netherlands last month.
However, after falling short at the British Championships last weekend, Ujah's participation in the European Championships in Zurich is in doubt.
James Dasaolu is Ujah's main rival for the third British sprinter's spot, the 26-year-old marking his return from injury with a time of 10.03 in the 'B' race Diamond League meeting in Lausanne last Thursday.
The final Diamond League meeting before the European Championships selection date is in London on Friday, July 11.
Athletes must achieve a qualifying time of 10.20 in the 100m - a criteria Ujah has already met - and will subsequently be assessed for selection based on other criteria set down by British Athletics.
The British Athletics qualifying guidelines state athletes that do not qualify automatically for the games will only be considered if they have 'the realistic potential' to win a medal at the European Championships, or finish in the top eight at the competition and go on to win a medal at a future championships.
The British Championships in Birmingham a fortnight ago doubled up as trials for the European Championships but Ujah lost out against a strong field, finishing third in a time of 10.18.
Automatic qualifying places instead went to Dwain Chambers and Harry Aikines-Aryeetey.
Athletes have until July 14 to achieve a qualification time and be up for consideration, with the team for the championships to be announced on Tuesday, July 15.