Federer and Nadal slammed over 'selfish' response to Australian Open smoke crisis

Canadian tennis player Brayden Schnur has moved to clarify his comments after labelling all-time greats Roger Federer and Rafael Nadal "selfish" for their silence on the smoke saga engulfing the Australian Open.

The world No.103, who is the third seed in the Open qualifying tournament, was scathing of officials after his first round win over Austrian Sebastian Ofner, which took over two hours in the smoky conditions that blanketed Melbourne Park on Wednesday.

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He said it was incumbent upon the biggest names is the sport to be the voice for lesser-known players.

"It's got to come from the top guys - Roger and Rafa are a little bit selfish in thinking about themselves and their careers," Schnur told AAP.

"Because they're near the end and all they're thinking about is their legacy and they're not thinking about the sport itself and trying to do what's good for the sport - so those guys need to step up."

Schnur later backtracked on his comments, apologising to Federer and Nadal.

“They are two players for whom I have enormous respect,” he wrote on Twitter.

“Their contributions to the sport have been remarkable and I am grateful for everything they’ve done.

“I misspoke when I used the term selfish, a poor choice of words that I regret.”

Schnur battled with conditions, which he described as like smoking a cigarette.

"You feel super dryness in your throat," he said.

"That's 100 per cent not normal and players who have asthma are at a huge disadvantage right now."

Organisers delayed play by three hours on Wednesday but the air quality index at 1pm when the players took to court was still graded as "unhealthy" due to the smoke from the bushfires in Victoria.

German Dustin Brown had to call for medical treatment and was given an asthma puffer to use during his loss to qualifying top seed Dennis Novak of Austria.

A distressed Brown didn't want to talk to media post-match.

On Tuesday Slovenia's Dalila Jakupovic was forced to retire while leading her match after she collapsed to her knees with a coughing fit.

Schnur said qualifiers were being treated poorly by Open organisers.

"This is why the players need to unite as one and make a decision for themselves because it's not healthy to play in," he said.

"You don't see the best soccer players in the world or the best golfers - if there's something wrong they postpone the game and in Melbourne they're just trying to shove us on the court because we're qualifiers."

Concerns for upcoming Australian Open

World No.2 Novak Djokovic, who is president of the ATP Player Council, has spoken of his concern for player welfare and questioned whether the tournament start should be delayed until conditions improved.

There was no option to move play to the venue's eight indoor courts, excluding the main air-conditioned arenas such as Rod Laver, Arena as there are permanent open vents.

While smoke delayed the start of play, it was suspended at 4.30pm when a storm hit Melbourne.

Victorian Jaimee Fourlis was mid-match against China's Fang Yin Xun, with the pair level at one set all when play was called off.

Queenslander Akira Santillan finished his match before the rain hit, falling to Frenchman Quentin Halys 6-3 7-6 (7-4).

Tennis Australia has defended its stance, saying it will continue to work with its medical team and the Bureau of Meteorology and Environment Protection Authority Victoria scientists when making decisions about whether it's safe to play.

TA said it has installed measuring devices on-site for air quality, with play cleared to continue during the opening round of qualifying.

Victoria's Chief Health Officer, Dr Brett Sutton, has called on the tournament to have an air quality policy but TA says the unprecedented fire crisis meant there hadn't been time.