Rodriguez was banned last season for 211 games by Major League Baseball for use of performance-enhancing drugs. An appeals hearing on the suspension concluded this week although a decision isn't expected until after the first of the year.
Rodriguez left the hearing Wednesday after arbitrator Fredric Horowitz refused to order MLB Commissioner Bud Selig to testify.
Attorney Joe Tacopina told WFAN, New York, evidence presented during the 12 days of the arbitration hearing is "overwhelming that [Rodriguez] went out of his way to make sure he was taking nutritional supplements" rather than banned substances.
"We have evidence -- it came out in the hearing and I can't go in detail on it -- that Tony Bosch was discussing with others Alex's nutritional supplementation, legal supplements, nothing to do with PEDs," Tacopina said Friday on WFAN.
Bosch is a central figure in the Biogenesis of America PED scandal. An investigation of MLS led the suspension of several high-profile players. All, except Rodriguez, accepted the suspensions without appeal.
Rodriguez's suspension, however, was more than four times as long as the other players'. His appeal allowed him to finish the season with the Yankees.
WFAN's Mike Francesa asked Rodriquez if he had used steroids in the Bosch case and the player denied he had and said he shouldn't have to serve "one inning" of a suspension.
Rodriguez has previously admitted to using steroids from 2001 to 2003.