In an email sent Thursday to the USA Gymnastics board, Scott Blackmun said an interim board must be assembled by Feb. 28, and that none of those members can be from the current board.
On Monday, three USA Gymnastics board members -- Chairman Paul Parilla, Vice Chairman Jay Binder and Treasurer Bitsy Kelley -- announced they were resigning.
Blackmun wrote that a non-interim board must be in place within a year, ESPN reported.
His request comes after a sexual abuse scandal that involved former national team doctor Larry Nassar, CNN reported. More than 150 women and girls claimed they were sexually abused by Nassar, including Olympic champions Aly Raisman, McKayla Maroney, Jordyn Wieber and Simone Biles.
Nassar was sentenced to 40 to 175 years in prison Wednesday. Nassar also pleaded guilty to 10 counts of first-degree criminal sexual conduct in November and received a 60-year sentence.
Blackmun said replacing the entire 21-member board of USA Gymnastics would guarantee a fresh start.
“We do not base these requirements on any knowledge that any individual USAG staff or board members had a role in fostering or obscuring Nassar's actions,” Blackmun wrote in his email. “Our position comes from a clear sense that USAG culture needs fundamental rebuilding.”
Blackmun also said that USAG must cooperate with an independent investigation to determine if anyone knew of abuse allegations against Nassar and neglected to report them.
In a statement Thursday night, USA Gymnastics said it "completely embraces" Blackmun's requirements.
“We understand that the requirements imposed by the letter will help us enhance our ability to accomplish change for the betterment of our organization, our athletes and our clubs,” USA Gymnastics said. “Our commitment is uncompromising and we hope everything we do makes this very clear.”