The inquiry comes after a report that Dr. Neal ElAttrache, the physician for the team, supported the U.F.C. star Conor McGregor in using performance-enhancing drugs while recovering from an injury.

© The Yomiuri Shimbun, via Associated Press Images

McGregor, the Ultimate Fighting Championship’s main attraction, had the support of the prominent sports physician Neal ElAttrache when he decided to use performance-enhancing drugs.

© John Locher/Associated Press