Absolutely - the reality is that the players have been sold up the creek by Essendon here. Yes, I understand "responsibility for your own body" and all that, but honestly, if you're at a club and they're asking you to take something, you're going to take it. Even if the players had queried it (and they may well have) they would have been told it's all above board, it's to aid recovery, etc. Make no mistake about it: the players are the victims in this scenario.
Unfortunately that won't get them out of the penalties that are coming to them. For some of them those penalties will bring an end their careers - for others it will kill it before it even starts. All of them will suffer large loss of income, sponsorship options, and massive blows to their reputations.
I hope every single one of them sues the pants off the administration at Essendon for putting them in this situation.