Zurich: UEFA have thrown out a protest by Fenerbahce, who complained that Champions League opponents Shakhtar Donetsk fielded Fred in last week`s tie despite allegations of a doping offence against the Brazilian midfielder.
"The protest has been dismissed," a UEFA spokesman said on Tuesday.
Shakhtar Donetsk coach Mircea Lucescu selected Fred for the third qualifying round first leg in Istanbul last Tuesday, which ended 0-0, while admitting the club had been advised by UEFA not to include him.
On Friday, the Brazilian Football Confederation (CBF) confirmed that Fred had tested positive for the masking agent hydrochlorothiazide during the Copa America in Chile.
The South American Football Confederation (CONMEBOL) has not yet announced any sanctions against the player or commented on the case.
Lucescu admitted he had been made aware of the possible doping violation but felt Fred was free to play as the club had yet to be issued with formal notification of any suspension.
The second leg is in Lviv on Wednesday.
Fred played in Brazil`s opening two fixtures at the June-July Copa America against Peru and Colombia but was dropped for the final group game against Venezuela and quarter-final defeat to Paraguay.
The CBF said in a statement that "we did not have this medicine available to us and it was not dispensed by the medical staff of the Brazilian national team".
However, the CBF said they were "supportive" of the player.