Nick Kyrgios has complained of the smell of marijuana during his second-round US Open victory over Benjamin Bonzi on Wednesday.
The 2022 Wimbledon finalist made the claim to the chair umpire late in the second set of his hard-fought 7-6 (7-3) 6-4 4-6 6-4 win over the Frenchman at Louis Armstrong Stadium.
The chair umpire remarked that the smell could be coming from the kitchen which Kyrgios retorted with "it was f***ing marijuana".
"People don't know I'm a heavy asthmatic," Kyrgios told reporters after the match.
"When I'm running side to side, I'm struggling to breathe, probably not something I want to be breathing in in between points.
"Yeah, US Open, it's a very different vibe to everywhere else. I feel like Wimbledon was so proper. Australian Open, you kind of expect it there, being an Aussie.
"But here, it's just like noisy. Point in, point out, I can't barely hear. Half the time I can't even hear my team because it's so noisy all the time."
The latter half of Kyrgios' second-round match coincided with major drawcard Serena Williams playing on Arthur Ashe Stadium against second seed Anett Kontaveit.
"Ashe was unbelievably noisy," Kyrgios added. "I couldn't hear anything. Constant jitter. Things going off, sirens.
"In Armstrong today, hearing trains and people. For someone that's struggled to focus in my career, I'm really trying hard to put my head down and play point by point, try to dig myself out of some certain situations.
"It's hard because there's a lot of distractions. Obviously a lot of heckling going on as well. People are saying things. I got to be very careful with what I say these days."
Kyrgios' win means he will take on American J.J. Wolf in the third round on Friday and the 23rd-seed Australian, who won August's Citi Open in Washington DC, said he was feeling motivated and more professional than ever.
"This year's been amazing in so many different ways," he said. "For my tennis, I kind of wanted to almost reinvent myself, get back to the top of the game where I know I belong.
"The Wimbledon final was a turning point I think for me mentally. If I won that match, I don't know where my motivation would have been at. Losing it and being so close, it was really tough for me to kind of swallow that.
"Winning Washington, winning so many matches, I just feel like I thought the pressure would be off me after winning Wimbledon. He's a Wimbledon finalist, he's nearly-over-the-hump-type thing.
"I didn't think I'd be putting this amount of pressure on myself. Every day I come in, I watch what I eat, I try and get sleep. Like every practice session I try and have good intent. I almost don't know who I am anymore, to be honest, because that's not me.
"I feel like I'm really professional right now. I never thought that the Wimbledon final would make me that way. I thought it would be the other way, the reverse, almost a bit lax and a bit chilled with it."