Bucs LB Kwon Alexander said he is appealing four-game suspension. Said he took an energy drink he didn't know contained anything banned.— Greg Auman (@gregauman) November 22, 2015
That's the kind of excuse we always hear after someone gets suspended for PEDs so I'd be skeptical of Alexander's claim, but it doesn't really matter: under the NFL PED policy, the way things got into your body doesn't matter. You are responsible for what's in there and unless you have a medical exemption, you will be suspended for it. If Alexander's defense is "I didn't know" he has no shot of winning the appeal.
Still, appealing the sentence will likely give him a reprieve of a couple of weeks during which the Bucs can still play him. Of course, that strategy could easily backfire: if the Bucs get to the playoffs, which is not unthinkable, having Alexander suspended then instead of during the regular season would be very unfortunate.