The venue for his first rally in nearly three weeks looked empty.
That's when George Gigicos, Trump's longtime advance man, got a call from Keith Schiller, the director of Oval Office operations who is almost always at Trump's side, asking Gigicos why the crowds were scarce. Gigicos explained that while TV correspondents were live early from the venue, the rally wouldn't start for several more hours and crowds had just begun to trickle in.
Soon after, Gigicos heard from Trump himself. The President was irate, warning his former director of White House advance who had since returned to his private contracting business, that the venue better be full by the time he arrived, two sources familiar with the discussions told CNN as they described the scene and the President's reaction.
The calls were nothing unusual for any of the advance officials who worked on Trump's rally-centric campaign. Gigicos himself knew Trump "wasn't happy," but was unconcerned, believing that he would work things out with his longtime boss, one source said.
But a few days later, Gigicos got a call from the Trump campaign's executive director Michael Glassner who informed him that Trump didn't want him working on his rallies anymore, a source familiar with the call told CNN. Gigicos had continued doing advance work for the Trump campaign as a contractor to the Republican National Committee since he left his job as director of White House advance on July 31.
Glassner did not respond to a CNN request for comment, and Gigcos declined to comment.
But even those familiar with the Phoenix blow-up said they have no doubt about Gigicos' future.
"George will be back," one source familiar with the matter said, noting that Trump's angry tirades are "not uncommon." "This is what (Trump) does. He tries to get under your skin."
"It wasn't great, but it also wasn't the worst thing I had ever seen," another source said.
Gigicos was one of a handful of aides who helmed the Trump campaign in its early stage and was the organizing force behind the hundreds of rallies Trump held throughout his campaign.
In that position, Gigicos often lived on edge.
Trump would regularly call Gigicos before rallies to ensure the rally would deliver the crowd size he had come to expect. And if it didn't meet those expectations, Gigicos would get upbraided by Trump, sources familiar with the Trump campaign said.
It wasn't just the crowd sizes. Trump would also get upset during the campaign if the venue for the rally were too small, the sources said.
The fire marshals were also frequent targets of Trump's ire, with Trump frequently calling them out from the stage and urging them to allow more people into the venue in spite of fire safety statutes.
During a January 2016 rally, Trump angrily complained about the faulty microphone at his podium, complaining about the "son of a bitch" who installed it.
And then, Trump added: "Do you hear that George? Don't pay him. Don't pay him," Trump said. "And you gotta be tough with your people because they'll pay, they don't care. They'll pay."