The sun shone in the first round of the Miami Masters 1000 on Wednesday, but there was a storm on court one as Vasek Pospisil let his anger explode at ATP Tour boss Andrea Gaudenzi before apologising. The Canadian's elimination by American qualifier Mackenzie McDonald (6-3, 4-6, 6-3) was more anecdotal than the incident late in the first set.

Pospisil first hit a ball off the court in frustration, before breaking a racket on the floor. Then, while serving in the first set at 5-3 and 40-15, he took a penalty point for abusive language, thereby losing the first set. Asked at the changeover by referee Arnaud Gabas why he was so angry, Pospisil said: "What's going on today? Yesterday, for an hour and a half, the ATP president yelled at me at a players' meeting for trying to unite the players."

"Get him out of here... Asshole... Why would I put up with this?" the 67th ranked player in the world went on to say, referring to Andrea Gaudenzi. A few hours later, the player expressed his regrets on Twitter. "I want to sincerely apologise for my behaviour on the court. I disrespected the game I love and I am truly sorry."

"By way of explanation, I was deeply troubled at a meeting between the players and ATP officials last night, and... I underestimated the weight of those emotions until I stepped on the court today. Again, I'm sorry for my behaviour and for the language I used," he added.

At the end of last summer, Pospisil, until then an ardent member of the ATP Players' Council, a body integrated into the institution, resigned to co-found, with world number one Novak Djokovic, the Professional Tennis Players Association (PTPA), a parallel and independent body. In November, he said in a podcast that the aim of the PTPA was to ensure that players were "represented properly". "With this organisation we really have the ability to influence major decisions that are made that affect our livelihoods."

As such, John Isner earlier on Wednesday highlighted players' questioning of the decline in prize money at tour tournaments, including the Miami Masters 1000, which has been cut from $1.35m for singles winners in 2019 to just over $300,000 this year. "There's a bit of misunderstanding about how these prize money are managed and why their amounts are what they are," he said, while understanding "that with the loss of revenue from ticketing, our prize money is going down" in times of a coronavirus pandemic.

"But some players are wondering why they have dropped so much. The Tour has implemented a strategy of keeping the prize money for the first rounds more or less the same, but the prize money for the quarter-finals, semi-finals and finals has been drastically reduced," said the American, who enters the tournament on Friday. Asked about the PTPA, of which he has also been a member since last year, Isner said that "at the end of the day, it could be healthy for the tour, although some people certainly don't agree with me.