Per Josh Katzenstein of the Times-Picayune, the NFL has already heard and denied Ingram's appeal.
The NFL announced on Tuesday that Ingram was suspended without pay for the first four games of the 2018 season after he violated the league's performance-enhancing drug policy.
David W. Jones, Ingram's agent, said in a statement released through the Saints' official website his client tested positive for a substance permitted by the NFL with a proper use exemption:
"At the end of the 2017 season, as a result of a NFL mandated random drug test, Mark Ingram tested positive for a substance that was not a performance enhancing substance, nor an illegal substance, but a substance in fact permissible with the proper use exemption with the NFL. He has vigorously challenged the test results through the arbitration process. The arbitrator's opinion is due on or before Wednesday, May 16. Upon having the opportunity to review the arbitrator's opinion, we will explore what further options are needed."
With Ingram suspended, the Saints will use Alvin Kamara as their primary running back. Kamara was named the Associated Press Offensive Rookie of the Year in 2017 after recording 1,554 yards from scrimmage and 14 total touchdowns.
Ingram will be eligible to participate in all of New Orleans' offseason activities and preseason games before his suspension begins. The two-time Pro Bowler will be eligible to return for their Oct. 8 game against the Washington Redskins.