FWIW, in early March when JA was pulled from the line-up after feeling dizzy/headache during warm up, a local pundit named Tartu accused Alvarez of being a juicer and that this was evidence of it. Small bruhaha ensued then blew over.
Fast forward to the latest River match where JA was pulled from the line-up after feeling a muscle strain during warm-up, the same pundit has popped up again with the accusations. If I understand it correctly, Tartu's take is that River arranges to pull JA from the line-up when they know he'll test positive after the match. Small bruhaha yada yada yada ... blowing over again. But ... expect some UK pundit down the road to dig up this story if they decide its time to attack City for something. shrug
BTW, if you're not aware, the kid presses like a maniac, runs like death is chasing him, relentlessly and effectively, so ... such performance puts a target on his back.