METAIRIE, La. — The New Orleans Saints’ defense will be even more depleted to start the 2021 season as standout defensive tackle David Onyemata has been suspended for the first six games of the regular season for violating the NFL’s policy on performance-enhancing substances.

Onyemata will be able to participate in all preseason practices and games. He will be eligible to return to the Saints’ active roster on Oct. 26, after the team’s Week 7 game at Seattle.

Earlier Friday, Onyemata announced on social media that he was facing a suspension for testing positive for a banned substance.

Onyemata, 28, was also suspended for one game to start the 2019 season after being issued a misdemeanor summons for marijuana possession. It’s unclear whether that affected the length of a new suspension, which appeared to fall under the category of performance-enhancing substances, based on his Instagram post.

“I was informed by the NFLPA yesterday that I have tested positive for a banned substance resulting in a suspension for part of the 2021 NFL season,” Onyemata wrote. “While I was certainly surprised and disappointed with this news, I am responsible for what I put in my body. As I have never knowingly taken anything that could cause a positive test, we are currently in the process of testing the supplements I was taking at the time of the test. Regardless, I am committed to being more aware of any medication and dietary supplements that may contain substances banned by the NFL.”

Onyemata has developed into one of the Saints’ best defensive players after being drafted in the fourth round out of the University of Manitoba in Canada in 2016. He is the anchor of a defensive tackle slate that was thinned out this offseason when New Orleans traded veteran Malcom Brown and let veteran Sheldon Rankins leave as a free agent.

The Saints have more than $10 million in salary-cap space to work with after some recent contract restructures and extensions. So it’s possible they could still look to add depth to the position before the start of training camp.

Cornerback Marshon Lattimore, a three-time Pro Bowler, could also face potential discipline from the NFL after being arrested on a stolen gun charge earlier this offseason. That’s another position New Orleans could still look to address in free agency after releasing fellow starter Janoris Jenkins during a salary-cap purge this offseason.

Onyemata is from Nigeria and had never played North American football until he went to college. But he has developed rapidly ever since. He became a full-time starter in 2019 and signed a three-year, $27 million extension as a free agent in 2020.

The 6-foot-4 300-pounder has been a huge part of the Saints’ stellar run defense, which ranks No. 1 in the NFL over the past four years combined. He also has improved as a pass-rusher, with a career-high 6.5 sacks in 2020 and a total of 14 sacks over the past three seasons.