KIEV: Shakhtar Donetsk coach Mircea Lucescu admitted he went against UEFA's wishes in fielding midfielder Fred in Tuesday's Champions League qualifier despite being aware of a possible doping violation hanging over the Brazilian international.

According to reports in his native Brazil, the 22-year-old had tested positive for a banned diuretic at the recent Copa America in Chile and faces a lengthy ban from the game should his second sample confirm the findings.

Lucescu, however, opted to start the midfielder in Tuesday's 0-0 draw at Fenerbahce in the first leg of their Champions League third qualifying round, dismissing UEFA's concerns while claiming he had yet to receive confirmation of any violation.

"Before the game, UEFA advised us not to include him but we had not received any official documents and this was just a verbal recommendation," the Romanian told reporters after the match in Istanbul.

"There is no specific statement on this matter for now and we are still waiting for the results of the B sample," he added.

"I have talked to the team and the player personally. When the official decision arrives, of course, we will stick to it."

Called up for the injured Luiz Gustavo, 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.

Lucescu believes the banned substance, the masking agent hydrochlorothiazide, could have been administered to the midfielder when he was on international duty.

"It is very hard to say what really happened. I guess the Brazil team doctor should be responsible for things like that," the coach added.

"I do not think a guy who can run 13 km per game needs pills but I will avoid commenting on the issue further until the results of the second test are known.

"However, it would be very sad if such a young player is suspended for some time."

Shakhtar host Fenerbahce in the second leg of their tie on Aug. 5 with the winners advancing to the Champions League playoff round for a place in the group stage of the lucrative tournament.