John Coppolella resigned as general manager of the Atlanta Braves amid a Major League Baseball investigation. (AP)

Last year, a prominent agent received a phone call from a 770 number. On the other end was John Coppolella, the general manager of the Atlanta Braves. He wanted to talk about one of the agent’s clients. The agent found this particularly curious, not because the Braves liked the player but because he was playing for a different organization and it was August, a full 2½ months before he would hit free agency. Never before had he seen a general manager so blatantly disregard tampering rules.

Over the course of Coppolella’s career – one that may have ended Monday as he resigned amid a Major League Baseball investigation into violations with international and domestic amateurs as well as tampering accusations, sources told Yahoo Sports – his disregard for rules fueled his ascent and hastened his downfall. As he climbed to the front-facing position in a prominent organization, Coppolella earned scorn from peers by ignoring the be-seen, not-heard industry convention and relying upon friendly media relationships to bolster his public reputation. His tenure as Braves GM eventually descended into chaos, with discord in the organization building and, eventually, erupting as anonymous accusations against him led to the investigation that forced his resignation, according to sources.

While the long-term fallout of Coppolella’s actions remains unclear, the focus of MLB’s investigation narrowed in recent days to the bundling of international amateur signing bonuses to circumvent spending restrictions, according to sources. The scope of the Braves’ scheme remains unclear, but a source familiar with it deemed it “significantly bigger” than a similar one employed by the Boston Red Sox in the 2015-16 signing period. To skirt rules that limited them to signing players for a maximum $300,000 bonus, Boston overpaid for bonuses on lesser players represented by the same buscon, or trainer, of more highly regarded players, to whom extra money was funneled. The five players signed in the scheme were declared free agents, and the Red Sox were banned from signing any international players for a year.

The Braves’ troubles could extend far deeper, according to sources. The investigation remains open and is expected to look into the signing of top prospect Kevin Maitan, a 17-year-old shortstop who received a $4.25 million bonus last year. If improprieties are discovered with Maitan’s signing, he, too, could be declared a free agent, according to multiple sources.

What’s increasingly evident, according to multiple Braves employees and others familiar with the investigation, is the chaos sowed during Coppolella’s tenure burbled with palace intrigue and leaves behind an organization in flux, even as it possesses arguably the best minor league system in the game.

Coppolella went into MLB’s Park Avenue office last week for an interview regarding a number of accusations, with a particular focus on the Braves’ pursuit of amateur talent, according to two sources. Over the following days, Braves employees wondered aloud whether Coppolella – who, with team president John Hart, had concentrated power, reshuffled personnel throughout the front office and within the last three weeks hired a new assistant GM and director of player personnel – would continue in his role.

The Atlanta Braves named John Coppolella general manager in October 2015. (AP)

The answer came Monday. The anonymous complaints levied with the league, according to sources, included accusations of bundling in Latin American, under-the-table benefits given to at least one draft pick and pre-draft deals struck months in advance – the latter two of which the league continues to investigate. One of Coppolella’s top lieutenants, longtime international scout Gordon Blakeley, resigned Monday as well.

When reached by Yahoo Sports on Monday, Coppolella declined comment.

Though the investigation into the Maitan signing is incomplete, it could have the starkest impact on the organization. Maitan, a switch hitter scouts called the best amateur to come out of Venezuela since Miguel Cabrera nearly two decades ago, headlined a class that, alongside the Braves’ strong 2016 draft, turned around a farm system that had stumbled under Coppolella’s predecessor, Frank Wren, and prompted an organizational rebuild.

For months leading up to the July 2, 2016 signing date, Maitan spent a significant amount of time living in a two-bedroom apartment near Miramar, Florida, with another teenage amateur the Braves eventually would sign, a source familiar with the arrangement told Yahoo Sports. While it is unclear whether the Braves funded Maitan’s time in the United States, he and the other player did not share a buscon and would have been connected by a third party.

Illicit activity in the international market is rampant enough in baseball that contract agreements with players as young as 15, technically illegal, are accepted as industry standard and signed when the player is 16. Bundling of bonuses and bringing players to the U.S. to work out before signing are considered egregious enough for the league to crack down with sanctions.

The domestic allegations are unlikely to carry the severity of penalty as the alleged international misdeeds, though the anonymous complaints offered a number of threads to investigate. One involves Drew Waters, a second-round pick this season whom the Braves allegedly offered under-the-table benefits to sign for under the slot value. In interviews with the league, Coppolella and Keith Grunewald, Waters’ agent, denied the allegations, saying that Coppolella’s offer of a car to bridge the difference between the $1.5 million he signed for and the $1.675 million slot value was made in jest, according to sources. When reached by Yahoo Sports, Grunewald declined comment.

Agents across the game said Coppolella is particularly aggressive in trying to cut pre-draft deals with amateur players, a practice in which other teams engage but is frowned upon and, taken in concert with other violations, could deepen the team’s penalties. It dovetails with Coppolella’s modus operandi as GM, in which his assertiveness – multiple GMs still recoil at the 2,000-plus word text messages he has sent – soured them.

Tampering is another gray area – and could be difficult to prove, as agents could be loath to cooperate with the league and potentially drag their clients into an investigation.

Then again, the dislike for Coppolella extends far and wide – some of it from baseball lifers who wondered how a Notre Dame graduate with no playing experience wound up in a GM chair at 36 years old, some from those who disliked the fashion in which he did it, relentlessly networking and trying to leverage himself into jobs through media contacts. Coppolella worked in the New York Yankees’ player-development system before joining Atlanta in 2006. He steadily ascended through the baseball-operations department, and upon the firing of Wren, with whom he butted heads, positioned himself as the heir apparent.

A year later, in October 2015, the Braves named Coppolella GM. Though Hart is the team president, Coppolella ran the team’s day-to-day operations, and his forcefulness grew over the past year, according to sources. While all draft rooms have contentious moments, multiple scouts said Coppolella’s anger boiled over at one point this year, further sullying a work environment that had degraded beyond repair.

Braves employees, even those who once were Coppolella loyalists, saw the proud organization of 14 consecutive division titles rotting from the inside. Now they wonder how, exactly, it’s going to weather the internal turmoil in concert with the eventual penalties levied by MLB.

“This place is totally [expletive] up,” one high-ranking Braves employee said last week. “I just hope when it blows up, it doesn’t take all of us down.”