METAIRIE, La. -- Saints safety Kenny Vaccaro is facing a four-game suspension due to a positive test for Adderall, a league source confirmed to ESPN NFL Insider Adam Schefter.

Vaccaro on Friday confirmed that he is now waiting for the league to test a B (second) sample before finding out whether he will be suspended, and deciding whether to appeal, the source told Schefter.

He declined to discuss any specific details of the reports. Adderall is a stimulant that is banned by the NFL unless players receive league approval to use it.

Kenny Vaccaro's versatility has allowed the Saints to use a three-safety set as their base defense in recent weeks. Christian Petersen/Getty Images

"I'm told not to make any comments on it right now until everything is final. I'm not gonna come out and say anything right now," Vaccaro said Friday. He acknowledged, though, that "it would be frustrating" if he wound up missing four games down the stretch after the Saints (4-4) have climbed back into playoff contention.

"We're on a run, we've won four of the last five," Vaccaro said. "But at the same time, it is what it is, and we're working it out right now."

The Saints host the Broncos on Sunday, then visit the Panthers on Thursday night.

In the meantime, Vaccaro can continue to play, and he practiced with the team Thursday and Friday. The Saints have not been notified about Vaccaro's situation by the NFL. The league also said that it has not been notified of a violation by the program administrators.

Saints coach Sean Payton cracked to the media Friday, "You guys will probably hear before me. You did yesterday. We're waiting, just like you guys are. "You guys can keep me posted."

Under NFL policy, neither the league nor the team would be notified of the situation unless both the A and B samples test positive.

Losing Vaccaro for four games would be a big blow for an improving Saints defense that was just starting to get some key players back healthy.

Vaccaro's versatility has allowed the Saints to use a three-safety set as their base defense in recent weeks.The 6-foot, 214-pounder, a first-round 2013 pick out of Texas, moves around from traditional strong safety to slot cornerback to linebacker at times. He has two official forced fumbles and assisted on a third in a crucial moment at San Diego in Week 4.

Vaccaro ranks second on the team with 43 tackles. He also has a fumble recovery, a pass defense and five quarterback hits.

The good news for the New Orleans defense is that safety is arguably its deepest position. Veteran Jairus Byrd and rookie Vonn Bell have shown improvement as the other two starters in recent weeks. And veteran Roman Harper was a starting strong safety for the past 10 years before taking a backup role with the Saints in 2016.

Also, the Saints could go back to a more traditional use of three cornerbacks in their nickel defense packages now that top CBs Delvin Breaux and Sterling Moore have returned from injuries.

The Saints have won four of their past five games after an 0-3 start. The defense still ranks 30th in the NFL in yards per game (408.5) and points per game (29.8) and 32nd in passing yards allowed per game (300).

But the Saints have allowed 27 points or fewer in each of their past three games. And after setting the NFL record with 45 touchdown passes allowed in 2015, the Saints have allowed only 11 through the first eight games this year.