Doping

I thought it was general knowledge that football has massive PED use. The Fuentes evidence pertaining to Spanish football clubs being buried, for example. People talking openly about plasma spinning and blood re-infusions. I've edited a public Q&A with Ian Wright talking about how Wenger came into Arsenal and revolutionised the place by doing things like vitamin injections.
The fact that there's almost no testing, but the pressure and the pay is higher than almost any other sport kind of suggests on its own that PED use would be rampant. I think it's not really talked about that much because the governing bodies have so much political influence, and preserving the status quo is more profitable for everyone. Also, it's not really seen as such an important factor in deciding results - it's supposed to be a game of skill, and people may think that PEDs don't help with the skills side of the game. Of course that's not true; the drugs help you perform at a higher level for longer.
To present a counter-argument to all that guff - the training football players do is utterly insane. There's so, so much gym work and conditioning work that the players today are worlds apart from those of 20 years ago. I've worked a lot on the Nike Academy stuff, which is a football academy for unsigned almost-could-be-pro players aged around 18ish. There's no way they're giving those kids PEDs (jesus, I hope not), but they go in skinny little kids and come out as brawny men... and that's even before they're fully physically developed. I think there's a lot of physical potential we didn't have the training knowledge to exploit before the age of blood doping arrived - that's the knowledge gap you may have heard Sky refer to when explaining how they've managed to become a top team so quickly.