A defamation lawsuit brought by sprinter Tyson Gay's ex-coach that claims the coach was falsely accused of supplying the athlete with performance-enhancing drugs has been put on hold until an arbitrator decides if the case should go to arbitration.

Jon Drummond, a former Olympic sprinter who coached the U.S. relay team at the 2012 LondonGames, sued the U.S. Anti-Doping Agency and Gay in May, denying that he had ever encouraged Gay or any athlete to use a banned substance.

The USADA has sought a lifetime ban against Drummond in connection with accusations he supplied Gay with performance-enhancing drugs. It has called Drummond's lawsuit a "baseless" effort to circumvent a mandatory arbitration process.

U.S. District Court Judge Reed O'Connor in Fort Worth on Wednesday said there was no question that anti-doping violations would be heard by an arbitrator, but it was unclear whether the defamation issues Drummond raised also should be heard in arbitration, court documents showed.

O'Connor issued a stay and said it would be up to an arbitrator to determine whether the defamation claims fall under the scope of anti-doping violations covered by arbitration.

Drummond, who coached Gay from 2007 to September 2012, is already arbitrating the agency's attempts to impose a lifetime ban.

Gay, the gold medal winner in the 100 and 200 meters and 4x100 meters relay at the Osaka world championships in 2007, tested positive in 2013 for a banned anabolic steroid.

He admitted his offense and co-operated with investigators and was handed a one-year ban in May, which was back-dated to June 23, 2013. Gay returned to competition in July.

Representatives of Gay and Drummond could not be reached immediately for comment.

USADA spokeswoman Annie Skinner said on Thursday arbitration was the appropriate place to address Drummond's case.

"No matter how famous or anonymous, each alleged offender is provided full due process, and any decisions regarding potential sanctions will ultimately be determined by independent arbitrators after a complete review of the evidence and testimony," Skinner said in a statement.