"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," agents Paul Bobbitt and David Jones said in a statement. "He has vigorously challenged the test results through the arbitration process."
An arbiter's decision is due by May 16.
"Upon having the opportunity to review the arbitrator's opinion, we will explore what further options are needed," Ingram's agents said.
Barring an overturned judgment, Ingram will sit out games against the Tampa Bay Buccaneers, Cleveland Browns, Atlanta Falcons and New York Giants. He will be eligible to return to the Saints' active roster on Monday, Oct. 1.
Although Ingram is eligible to participate in all offseason practices and preseason games, the NFL Network, citing a source, reported that he skipped voluntary workouts and plans to bypass the Saints' organized team activities because he wants a new contract.
Ingram was selected to his second Pro Bowl after rushing for career highs in yards (1,124) and touchdowns (12). He also caught 58 passes for 416 yards.
The 28-year-old Ingram has rushed for over 1,000 yards in back-to-back seasons and has registered 154 receptions over the past three seasons, including a career-high 58 in 2017.
New Orleans does have a capable replacement in the electrifying Alvin Kamara, who was named the NFL Rookie of the Year last season.
Kamara rushed for 728 yards and eight touchdowns, averaging 6.1 yards per carry, and also amassed 81 receptions for five more scores in his rookie campaign.
New Orleans' ground game ranked fifth in the NFL with an average of 129.4 yards per game last season while leading the league with 23 rushing touchdowns and an average of 4.7 yards per carry.
Ingram has started 58 of 94 games since the Saints drafted him in the first round in 2011. He has rushed for 5,362 yards and 44 touchdowns while adding 207 catches and four more scores.