Alonso, who moved with his family to Florida from Cuba at 8 years old, mashes doubles as well as taters from the left side and has uncommon plate discipline.
A natural first baseman -- creating a San Diego surplus there with Anthony Rizzo -- Alonso was the jewel in a four-player holiday package shipped to the border town by Cincinnati, which landed high-end starter Mat Latos.
The Reds have another deal in the oven for southpaw Sean Marshall, a back-end bullpen arm, with starter Travis Wood and two prospects reportedly heading to the Cubs. This is a fairly standard need-for-need exchange that should help both clubs.
The Latos swap is a knee-buckler. Certainly, from a historical perspective, this has to be the most intriguing trade of the winter.
For the Reds, who have contending components in place, it's high-risk, high-reward of the highest order. They are going for the gusto, decisively, dancing in the face of some heavy forces in their past by unloading Alonso, who has star qualities.
Joining manager Bud Black's pitching stable along with Boxberger is 28-year-old right-hander Edinson Volquez, the one proven commodity in the quartet heading west.
This is where it gets really weird for Reds partisans.
Volquez is the fellow that the Reds imported following the 2007 season, when they needed an arm and owned a gifted outfielder with an extremely troubled past, coming off an impressive rookie season at age 26.
Texas, which included reliever Danny Herrera in the deal, was willing to take a chance on the guy with the hellish past, hoping that Josh Hamilton would discover a little slice of heaven in the Lone Star State.
Finding faith and grace, Hamilton became an American League Most Valuable Player in 2010 and a dominant presence on a Rangers club that has reached the past two World Series, coming within an out of winning it all two months ago.
Volquez gave Cincinnati one terrific season -- 17-6 with a 3.21 ERA in 2008 -- and mediocrity, going 13-12 in 41 starts from 2009 through 2011. Herrera was 5-7 with a 3.62 ERA in 113 games for the Reds.
As frustrating as it is for Reds fans to imagine the damage that Hamilton and Joey Votto could have done together, this isn't even the worst trade of a position player for a pitcher in franchise history.
That distinction goes to the Dec. 9, 1965, detachment of Frank Robinson to Baltimore. The Orioles claimed the Hall of Fame slugger for right-handers Milt Pappas and Jack Baldschun and outfielder Dick Simpson.
Robinson, burning to show Reds management that he was far from done at age 30, led the Orioles to four World Series appearances and two championships in six seasons, winning a Triple Crown in 1966.
Pappas -- the featured attraction from Cincinnati's end -- was a solid starter, going 30-29 with a 4.04 ERA in 2 1/2 seasons.
Baldschun was 1-5 with a 5.25 ERA in two seasons of relief with the Reds. Simpson, also in two seasons, batted .246 with five homers and 20 RBIs.
Separated by 42 years, the Reds let go of two of the best athletes to play the game, both in what turned out to be their physical primes.
The administration now in place in Cincinnati, led by general manager Walt Jocketty and manager Dusty Baker, is well acquainted with history and how harsh media and fan judgments can be. You have to respect the Reds for having the nerve to put themselves in this position with the Latos deal.
There is no suggestion here that Alonso, blocked by Votto at first in Cincinnati, will rise to the levels of Josh Hamilton and Frank Robinson. But if Alonso flourishes and Grandal and Boxberger also deliver, Latos must elevate the Reds.
Under club control for four years, Latos, 24, has ace stuff. His power arm will remind Baker of Bobby Welch, a teammate from his Dodgers days.
Welch, who lived as hard as he threw (high 90s) as a kid, straightened himself out and became a star, winning 211 games and a Cy Young Award with Oakland as a 27-game winner in 1990. He appeared in 13 postseason series.
Welch always credited Baker, the Dodgers' clubhouse leader, for guiding him and mentoring him. If Latos listens and learns, he too can benefit from his manager's wisdom.
"There's a lot of talent and a lot of potential to compete for years to come," Latos said of the Reds, "and I'm excited to come in and play with these guys."
At midseason, Baker was convinced that his club would get it together and make a run at the National League Central title. Instead it was St. Louis making all that magic, with the Reds falling by the wayside in third place.
With Latos and Johnny Cueto atop a deep rotation and Marshall presumably anchoring the bullpen, the Reds are much better than they were when the 2011 season ended.
Sometimes, when you feel you're close, you do what you believe is right -- fully aware of the heavy risks involved.
History might inform you, but it can't imprison you.
Lyle Spencer is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.