The fate of Alex Rodriguez lies largely in the credibility of Anthony Bosch, so it’s no surprise Team A-Rod continues to pick at that scab.

Rodriguez has acquired an affidavit from Robert Davis Miller attesting that Bosch, who testified for nearly five days in the appeal hearing for Rodriguez’s 211-game suspension against Major League Baseball, used cocaine “on almost a daily basis but at least many times per week and month” from the summer of 2012 through the spring of 2013.

Furthermore, The Post has received a photo which purports to show Bosch sitting with another man at a table on which are two small bags of unidentified white powder.

Miller is the same man who asserts Bosch told him MLB was paying him a total of $5 million in monthly installments; that, too, is in the affidavit. Bosch has denied receiving payment for his cooperation. As The Post reported last month, Miller is a convicted drug dealer.

Team A-Rod didn’t call Miller as a witness during the arbitration hearing, so this affidavit — as well as of those of other people who shared their experiences of alleged MLB investigator misbehavior — would come into play only if Rodriguez can get a federal or state court to entertain his lawsuit against MLB.