Masi took up the position three years ago following the untimely death of Charlie Whiting on the eve of the Australian Grand Prix.
It's now been decided that the race director role will be filled by two people, supported by the experienced Herbie Blash and a virtual race control room.
“He's a personal friend,” Arocca told Speedcafe.com of his relationship with Masi.
“I've known him as long as I've been involved in motorsport, which goes back 10 years, and we've become good buddies.
“So it's personally disappointing and devastating for me to see what has occurred.
“I've got to be very mindful that I'm not part of a process, I wasn't privy to the information that was being considered by the FIA, but on a personal level if you see a mate, and particularly an Australian, have to go through what he's gone through, I've got a certain amount of empathy and disappointment and frustration and anger.”
Masi rose through the ranks of Motorsport Australia before being hand picked by Whiting as his replacement as F1 race director.
According to Arocca, Whiting spotted a number of qualities that stood him in good stead for the role.
“Unlike many others, he's actually been administering, involved in managing motorsport for many, many years. That's a good thing. He's got an extensive background and history,” Arocca said of Masi.
“He's very insightful, intelligent, and able to make decisions in the heat of a moment.
“That's something that people may have lost in some of the debate.
“It's really easy to be a critic on the sidelines thinking what he went through when he was making those decisions.
“There would be other people that would be completely paralysed in exactly the same circumstances.
“He made the call. That is the first character trait of a strong leader.”
Arocca also revealed that he'd exchanged text messages with Masi following the announcement.
“I can't speak on his behalf, but I would say that one of the more difficult elements of all this, let's call it this incident, happened late last year, some three months ago now, and to a large degree it's been a process that hasn't leant itself to really being in a good frame of mind,” he said when asked how his former colleague was doing.
“It's been a tortuous two or three months of discussion, debate, criticism, public airing of view.
“You have to have a hide that's pretty thick to be able to withstand all that and come out the other end feeling okay.
“Gladly, based on the fact that he responded this morning, and he was obviously pretty flat, he's a man who's got fantastic resilience.”
According to Mohammend Ben Sulayem, the recently elected FIA president, Masi will be offered a new role within the sport's governing body.
However, many within the industry suggest it will be just one of a number of offers on the table in world motorsport.
“We would love to tap into his knowledge at any level,” said Arocca when asked if Motorsport Australia would attempt to lure him back.
“He's just an elite talent that would be wasted to the sport if he's not used in some capacity, and so we'll keep an open mind.
“At the moment, we're obviously concentrating on the year ahead, and when he's decided what he wants to do, no doubt amongst many others, he'll be contact by not only us but by others.
“He's just such, I'll use the word elite. He's officiated for three years in one of the most public, high pressure sporting events with an element of danger in the world, and he's done it during a pandemic with significant levels of travel, stress, other duties, and in my view that stands well on his resume for any employer anywhere in the world.”