Did the NFL fail to follow proper protocol while administering Julian Edelman’s performance-enhancing drug test? That’s what the New England Patriots wide receiver is claiming, according to a report.

Edelman, who is facing a four-game suspension for violating the NFL’s PED policy, “plans to mount a vigorous defense” at his appeal hearing Monday, ESPN’s Dan Graziano reported early Monday morning.

“As the MMQB reported a few days (after news of the suspension broke June 7), the substance for which Edelman tested positive wasn’t one the league’s drug testers recognized,” Graziano wrote. “That remains one of two key issues at the heart of his appeal.

“The other, according to a source, involves a mishandling of the documentation and delivery of Edelman’s test results. During the course of the investigation, it was learned that the NFL had made mistakes in the manner in which those test results were handled. Edelman is arguing that the mishandling of the evidence is one of the reasons he should be exonerated.”

Graziano also reported that Edelman hired attorney Alex Spiro to assist in his appeal and raised the possibility of Edelman taking his case to federal court if the NFL upholds his suspension.

“Given the addition of Spiro to the defense, and the recent history between the Patriots and the NFL in the Tom Brady Deflategate matter, it’s not out of the question that Edelman could end up pursuing an appeal of his case in federal court if the arbitration does not go his way,” Graziano wrote.

In an apology posted June 8 on Instagram, Edelman claimed he did not know what caused his positive test.

“I am very sorry,” he wrote. “I don’t know what happened. I’ve taken many, many tests obviously over the course of my career, and nothing like this has ever happened.”

Edelman, who turned 32 last month, missed all of the 2017 season after tearing his ACL in a preseason game. He was the Patriots’ leading receiver in 2016, catching 98 passes for a career-high 1,106 yards and three touchdowns.

Thumbnail photo via Bob DeChiara/USA TODAY Sports Images