Arsenal manager Arsene Wenger has claimed that he has witnessed evidence of doping in football.
The Gunners boss said that he has encountered "many teams" that have used performance-enhancing drugs during his 30 years as a coach.
"I try to be faithful to the values that I believe to be important in life and to pass them on to others," he told French newspaper L'Equipe.
"In 30 years as a manager, I've never had my players injected to make them better. I never gave them any product that would help enhance their performance. I'm proud of that. I've played against many teams that weren't in that frame of mind."
Dinamo Zagreb midfielder Arijan Ademi failed a doping test following the Croatian side's 2-1 win against Arsenal in the Champions League last September.
"For me, the beauty of sport is that everyone wants to win, but there will only be one winner. We have reached an era in which we glorify the winner, without looking at the means or the method," Wenger added.
"And, 10 years later we realise the guy was a cheat. And during that time, the one that came second suffered. He didn't get recognition. And, with all that's been said about them, they can be very unhappy."
Wenger's comments come amid widespread allegations of doping and cover-ups in Russian athletics.
