Even though the Angels paid heavily to get him in this three-for-two deal, the lingering question is how the Braves could deal away a 26-year-old defensive wizard who is signed for five more years and just took a step forward as a hitter.
Also, just how crazy is this Hot Stove season going to be? This Simmons trade percolated at the General Managers Meetings in Boca Raton, Fla., and it came to fruition as executives were returning to their respective corners. It's the type of a deal that could have tied up rumor sites for weeks both before and after the Winter Meetings, but this doesn't appear to be a normal market.
With the Royals and Mets meeting in the World Series, there are almost no teams that don't picture themselves in the fight next fall. Every team has needs, and even though there are almost 200 free agents available, teams are working with each other to try to find trades that make sense.
These are going to be interesting weeks as teams head toward the Winter Meetings in Nashville, Tenn. The "you snooze, you lose'' rule appears to be in place as early as it has ever been.
But as for the transaction in question, give Billy Eppler credit for hitting a home run in his first deal as the Angels' general manager. He inherited a built-to-win team that missed the postseason this year and has made it better for at least the next few seasons -- otherwise known as the best chance to make owner Arte Moreno's investment in Albert Pujols pay off.
Simmons, who just received the Wilson Defensive Player of the Year Award, worked wonders to keep the ERA of Atlanta's patchwork pitching staff at 4.41 last season. He should be a godsend for an Angels team that features a middle-of-the-pack pitching staff, both in terms of overall results and, significantly, strikeouts.
Aybar was a solid presence in the middle of the Halos' infield since 2008. He was reliable and was a tough out, especially by shortstop's standards. Manager Mike Scioscia hit Aybar cleanup at times in the disappointing 2015 season, and fifth for long stretches of time. But he didn't win many games with his glove, and Simmons will.
Eppler understood that as well as anyone, having spent much of the past five years trying to figure out how the Yankees would make the transition from Derek Jeter to someone less legendary. Eppler's legwork and research eventually led the Yanks to Didi Gregorius, but you've got to think that Simmons would have been in New York last season had the Braves been as willing to deal him as they became over the course of the 67-95 season.
Simmons, who had signed a seven-year, $58 million deal with the Braves before the 2004 season, couldn't have been happy about management's decision to rebuild while awaiting the move into a new stadium. He sounded thrilled on Thursday night about the chance to play alongside Mike Trout, Kole Calhoun, Pujols and the other Angels (although when you look at the team's overall inventory, you can see there's still a lot more work for Eppler to do).
Simmons thrilled team president John Schuerholz and manager Fredi Gonzalez when he hit 17 homers and won a Gold Glove in 2013, his first full season. But much of that power came from teams continually testing him with fastballs. They've learned how to pitch to Simmons, and he hasn't been the same two-way player. But he did raise his on-base percentage from .286 to .321 last season, helping John Coppolella, who was just promoted from assistant GM to GM under John Hart and Schuerholz, sell Simmons' potential as a hitter as well as fielding prowess.
According to FanGraphs, Simmons was good for a Majors-best 25 defensive runs saved at shortstop last season. It was the third year in a row that he's been ranked as the top shortstop, and there's nobody else in the group photo.
Simmons has a plus-94 in DRS over the past three seasons; the next-best figures for that time period belong to Brandon Crawford and Zack Cozart, at a mere plus-30. That's what makes Simmons such a commodity, especially at age 26, signed for five more seasons.
Because of the questions about Simmons' bat, as well as the ongoing rebuild, the Braves are happy to get rid of a contract that guarantees him $11 million in 2018, $13 million in '19 and $15 million in '20. They can spin Aybar to one of the few teams looking for shortstops (the White Sox, Padres, Rays and maybe Twins), but there aren't as many of those as you might think.
There are a lot of good shortstops around. Maybe that's why the Braves are willing to consider using Daniel Castro or even Jace Peterson as a bridge to their rising shortstop prospect, Ozhaino Albies, an intriguing two-way player who spent 2015 in the Class A South Atlantic League. But Simmons is the Ozzie Smith of his generation.
Speaking of the Wizard of Oz, the Hall of Famer was 26 when the Padres traded him to the Cardinals. He helped them beat the Brewers in the World Series in 1982, his first season with St. Louis.
So there's the precedent for Simmons. Whether he lives up to it or not, you know he's going to have fun trying.
Phil Rogers is a columnist for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.