New details have emerged about Julian Edelman’s failed performance-enhancing drug test.

The New England Patriots wide receiver’s positive test “was triggered by a substance that wasn’t immediately recognizable,” Albert Breer of The MMQB reported Monday.

“There are scientists analyzing (the substance),” Breer added.

Breer also reported the unknown substance couldn’t have been a stimulant like Adderall.

“As to the timing, the test did happen during the offseason (a couple months ago), which means it’s not for any kind of stimulant,” he wrote. “You might remember the rash of players saying they got popped for Adderall — the rules have changed now so that offseason use of stimulants falls under the substances of abuse policy, rather than the PED policy.”

Edelman is facing a four-game suspension, which he is appealing. He missed all of last season with a torn ACL but has been practicing with the Patriots this spring.’s Michaela Vernava has the details in the Xfinity X1 Report, which you can watch above.

Thumbnail photo via Mark J. Rebilas/USA TODAY Sports Images