The Raiders fear potential NFL discipline might be imminent for wide receiver Martavis Bryant, sources said Thursday. It is believed to pertain to the NFL’s substance-abuse policy.

Oakland Raiders wide receiver Martavis Bryant leaps for a pass at the NFL football team's minicamp Wednesday, June 13, 2018, in Alameda, Calif. (AP Photo/Rich Pedroncelli)

Oakland Raiders' Martavis Bryant catches a pass during NFL football practice on Tuesday, May 22, 2018, at the team's training facility in Alameda, Calif. (AP Photo/Ben Margot)

Oakland Raiders wide receiver Martavis Bryant smiles during an NFL football media conference Friday, April 27, 2018, in Alameda, Calif. (AP Photo/Ben Margot)

ALAMEDA, Calif. — The Raiders fear potential NFL discipline might be imminent for wide receiver Martavis Bryant, sources said Thursday, inciting internal uneasiness at the conclusion of an otherwise encouraging spring workout program.

Multiple team officials declined comment as they left for a weekslong break before training camp, but they acknowledged the club is awaiting final word on the situation. It is believed to pertain to the NFL’s substance-abuse policy.

Bryant, 26, missed the entire 2016 season after repeated policy violations. That he again might be liable to discipline does not signify a failed drug test. Failure to attend a scheduled exam can evoke an infraction, too.

On April 26, the Raiders traded a 2018 third-round pick to acquire Bryant from the Pittsburgh Steelers during the first round of the NFL draft. The team was intrigued with the talented 6-foot-4-inch, 211-pound deep threat. It also understood the risk.

Any future misstep with the substance-abuse policy might prompt a year or longer suspension. The 2014 fourth-round pick from Clemson is entering the final year of his rookie contract, too. He is scheduled to become a free agent in March.

On April 27, Bryant said during a news conference that he embraced a “clean slate and fresh start” in Oakland. He said that he would take the proper steps to ensure he had a long-term Raiders future.

“Just by handling my business as a man,” Bryant said. “It’s not my first rodeo. I’ve had my difficulties in my past, but I’ve come a long way from that. It’s all about keeping the right resources around me and continuing to stay on the right path. I’m going to make sure I get that done.”

Word of possible league discipline has reached various corners of the locker room.

Bryant practiced Tuesday and Wednesday. He did not participate in Thursday’s conclusion to minicamp.

The Raiders traded for him shortly after collecting the needed compensation.

It came courtesy of the Arizona Cardinals, who moved up five spots to select former UCLA quarterback Josh Rosen at No. 10 overall. The Raiders received a third- and fifth-round choice in exchange. Minutes later, they drafted former UCLA left tackle Kolton Miller at No. 15 overall and flipped the third-round pick to Pittsburgh for Bryant.

Bryant showcased his ability this spring, flashing innate separation ability against the team’s secondary. He represents an added dimension for the Raiders, who do not possess someone else with his rare size-speed profile.

Those physical traits are one part to what inspired coach Jon Gruden’s optimism.

“I’ve seen the Steelers practice in my previous position,” Gruden said April 27. “The man knows how to practice. The guy knows how to prepare. He’s been through a lot in his life, and he’s got something to prove, and I think we’re catching him at the right time. (Steelers coach) Mike Tomlin is a friend of mine. I coached with Mike, and I got a lot of confidence in this young man.

“I think a change of scenery can unleash his greatness. Putting him in the lineup with Jordy Nelson and Amari Cooper and Jared Cook and Derek Carr excites me a lot.”

In three seasons, Bryant has 126 receptions for 1,917 yards and 17 touchdowns. He recorded 50 catches, 603 yards and three scores in 2017.

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Contact reporter Michael Gehlken at mgehlken@reviewjournal.com. Follow @GehlkenNFL on Twitter.