Aren't there big rumours regarding pep guardiola and his use of these?
Guardiola was suspended for Nandrolone use during his time in Brescia. It got overturned after an appeal.
Dr Doping Eufemiano Fuentes was allegedly used by Barcelona and Real Madrid. Fuentes quotes:
"I worked with Spanish first and second division clubs,"
"I worked with several clubs at the same time, sometimes directly with the footballers themselves, sometimes by sharing my knowledge with the teams doctors.
Fuentes was asked directly which football clubs he had worked with. "I can't tell, I have received death threats," he said.
For recovery times (especially when playing 3 games in a week) it is a massive benefit. There's no risk in Spain as they don't do blood testing which means you can take all the epo you like.
Of course EPO would have a huge effect on a footballer.
I use to run a lot before in the gym usually an hour or two a day but mostly just 10-20km bursts. The few times I tried EPO I would easily knock 10-15 mins off my time. If it can have that effect on a medium fit guy like me on a threadmill I cannot imagine the boost a footballer would get from it during a match.