The New York Yankees hand-delivered a letter to Alex Rodriguez prior to Friday night's game, informing him that he will be disciplined for seeking a second opinion on an injury without club approval, according to sources.

Rodriguez and the Yankees fought publicly late in July over the health of his quadriceps.

Without officially informing the team, Rodriguez had orthopedic surgeon Dr. Michael Gross of Hackensack University Medical Center examine his MRI.

The letter did not specify the exact nature of the discipline.

Rodriguez is appealing his 211-game suspension for violating Major League Baseball's drug policy. He did not speak to reporters Friday.