Novak Djokovic gets why some tennis players question whether there's a double standard in the sport after Jannik Sinner was not suspended despite twice testing positive for steroids, and said Saturday that he agrees that there is "a lack of consistency."

Sinner tested positive twice in March for an anabolic steroid, but the International Tennis Integrity Agency determined the banned performance-enhancer entered his system unintentionally through a massage from his physiotherapist.

The ruling was announced Tuesday, less than a week before Sinner begins the US Open as the No. 1-seeded man. Djokovic, who won the tournament last year for his men's-record 24th Grand Slam singles title, is the No. 2 seed.

"I understand the frustration of the players is there, because of a lack of consistency," Djokovic said. "As I understood, his case was cleared the moment basically it was announced."

Some players commented on social media after the news broke, wondering if Sinner caught a break because of his standing as one of the best players in the game.

"We see a lack of standardized and clear protocols. I can understand the sentiments of a lot of players that are questioning whether they are treated the same," Djokovic said.

Djokovic said the Professional Tennis Players Association, which he co-founded, advocates on behalf of players for clear and fair protocols and standardized approaches to cases.

"Many players ... have had similar or pretty much the same cases, where they haven't had the same outcome," Djokovic said, "and now the question is whether it is a case of the funds -- whether a player can afford to pay a significant amount of money for a law firm that would then more efficiently represent his or her case."

Carlos Alcaraz, the 2022 US Open champion, said Sinner's case was a delicate issue.

"I think there's something behind this that a lot of people doesn't know. I don't even know. In the end it's something very difficult to talk about," Alcaraz said.

"In the end, he tested positive, but there must be a reason that allowed him to keep playing that we don't know. So I cannot talk a lot about it. He was declared innocent and so we have Jannik in the tournament, and so there's not much to talk about and I'm no position to add anything else."