(CNN) -- New York Yankees star Alex Rodriguez had a "consulting relationship" with a Florida anti-aging clinic accused of providing banned drugs to baseball players, but there's no evidence he did anything to violate baseball's Joint Drug Agreement, one of his attorneys told CNN Monday.
Rodriguez is appealing a 211-game suspension that Major League Baseball levied against him this month, with the league accusing him of taking performance-enhancing drugs and having ties to the now-shuttered Biogenesis clinic.
Attorney Joe Tacopina said Rodriguez was one of many athletes who consulted for Biogenesis.
"Clearly there was a relationship -- a consulting relationship," Tacopina said. "I mean, Biogenesis, that lab has consulted with many professional athletes. Not every single one of those athletes has been accused of or found guilty of using illegal substances."
Tacopina declined to give further details about the relationship, citing confidentiality concerns. But he said, "They have no scientific evidence to prove that Alex Rodriguez did anything to violate" baseball's drug agreement.
"It's witness testimony from one witness -- a witness who's not going to be available, in my prediction, to either testify in arbitration or at some federal proceeding," he said.
When asked why he wouldn't say unequivocally that Rodriguez didn't use performance-enhancing drugs, Tacopina again cited confidentiality considerations.
"If I utter those words, I've just violated the confidentiality clause of the JDA -- that's the bottom line," he said. "... If you're a supporter or a detractor, what happened to him is not fair by anyone's standards. It's clearly a vendetta, it's clearly a witch hunt to get him 211 games -- not justifiable under anyone's scenario that is being objective."
Apparently in response to comments like these, Rob Manfred, Major League Baseball's executive vice president of economics and league affairs, sent Tacopina a letter on Monday, offering to waive confidentiality provisions.
"While we believe that your public comments are already in breach of the confidentiality provisions of Major League Baseball's Joint Drug Prevention and Treatment Program (the "Program"), we will agree to waive those provisions as they apply to both Rodriguez and the Office of Commissioner of Baseball with respect to Rodriguez's entire history under the Program, including, but not limited to, his testing history, test results, violations of the Program, and all information and evidence relating to Rodriguez's treatment by Anthony Bosch, Anthony Galea and Victor Conte," he wrote.
Tacopina was not immediately available to comment on the contents of the letter.
Rodriguez is playing during the appeal, which the players' union filed on his behalf two days after the suspension was announced.
CNN's Adam Reiss contributed to this report.