CHICAGO -- Fans and pundits alike point to the trade on Dec. 6, 2016, sending White Sox ace Chris Sale to Boston for a four-player return including third baseman Yoan Moncada and right-handed pitcher Michael Kopech as the beginning of the franchise’s rebuild.

But in reality, it was the White Sox trade of Fernando Tatis Jr. a few months earlier that changed the team’s focus. The No. 2 prospect overall per MLB Pipeline, Tatis Jr. posted six home runs, six stolen bases and a .910 OPS as the 20-year-old starting shortstop for the Padres before straining his hamstring.

“That was probably the last deal we made with having a short-term mindset in mind,” said White Sox general manager Rick Hahn during a recent interview with MLB.com. “Ultimately when this thing gets right, we are going to once again have a shorter time arising goal with our trades. It doesn’t mean you want to make a deal that haunts you for the long term, obviously.”

The Tatis trade came on June 4, 2016, after the White Sox had dropped a 7-4 decision in Detroit. Following an impressive 23-10 start to that particular season, including with it a six-game lead in the American League Central, the White Sox dipped to 29-27 with this setback. They were trying to add starting-pitching depth missing within the organization as John Danks had been released after four rough starts and Mat Latos struggled.

They moved Tatis Jr., who was an international signing a little less than one year before, and right-handed hurler Erik Johnson for veteran starter James Shields. Shields became a mentor to burgeoning White Sox hurlers and made 34 starts and topped 200 innings in 2018, but he did not help the cause in ’16.

In fact, Shields finished with a 6.77 ERA over 22 starts for the White Sox, and Chicago ended with a 78-84 record in what would be Robin Ventura’s last year as manager. With each powerfully furious step Tatis Jr. made through the Padres’ system, this deal became tougher and tougher to forget.

“Yeah, yeah,” said Hahn with a resigned smile of the deal being frequently discussed. “I’m aware of that. Looking at Tatis, I view that as a great success for our international scouting program. Work that Marco Paddy and his people did to identify him and acquire him should be commended. Although he was only with us for roughly a year or so, the work that our player-development people did with him was very good as well. And there were people in the organization who spoke highly of his potential.

“No one went into that deal ignorant of what this kid could possibly turn into,” Hahn said. “At the same time, the decision to make that trade was motivated by elements within the organization we are trying to avoid as we complete this rebuild, as we get to the other side of the rebuild.”

Clear progress has been made in Year 3 of the White Sox rebuild. Take a look at the development of Moncada, shortstop Tim Anderson and right-handed starters Lucas Giolito and Reynaldo Lopez, along with the Major League arrival of left fielder Eloy Jimenez and the Minor League growth of outfielder Luis Robert and right-hander Dylan Cease, as a few examples.

A couple of these top-notch young White Sox were asked about in trade possibilities this past offseason. Those deals focused on acquiring other young players, although according to Hahn, one deal was for a more veteran player but with a few years of control. It was really the first time the White Sox thought about potentially parting with one of the guys who was a possible long-term piece.

“We didn’t do it, but it was a preview of what’s to come here in the coming one to two years,” Hahn said. “Again, we are not in a position where it makes sense to move the young talent.

“When the time comes, we hope to be dealing from a position of strength. Obviously with a position of strength literally meaning we have a lot of outfielders for example. So if we move an outfielder, we arguably have alternatives.”

Rebuild missteps don’t derail championships, as shown by the Astros, Royals and Cubs previously, but the White Sox can’t afford to miss when they graduate to the phase of trading top young talent for finishing pieces. It’s a concept not lost on Hahn.

“If you don’t learn from your mistakes, you are going to be bound to repeat them,” Hahn said. “We spent a good amount of time analyzing exactly what the events were that led up to the decision to make such a trade [with Tatis Jr.], as well as the evaluations that went into that actual deal.

“I’m not going to say we are going to be beyond reproach. But I do think we have a very good understanding of what led to that one and the pitfalls that led us down that path and those will be avoided next time around.”