For the A's, it probably means Ike Davis gets non-tendered as they go with an Alonso/Mark Canha platoon at first base in 2016. For the Padres, it's a reminder of a bad decision back in the 2011-12 offseason. Josh Byrnes was the general manager then, just promoted from assistant GM after having previously served as GM of the Diamondbacks.
On Dec. 17, the Padres and Reds made a big trade: San Diego sent 24-year-old right-hander Mat Latos to Cincinnati in exchange for Alonso, Yasmani Grandal, Edinson Volquez and Brad Boxberger. In retrospect, it was a pretty good haul of talent. Since the trade, Latos has been worth 8.6 WAR and the other four have combined for 17.4 WAR.
Alonso was a key to the deal. He had been the seventh overall pick in the draft in 2008, rated the No. 65 prospect by Keith Law and No. 73 by Baseball America prior to 2011, but blocked by Joey Votto in Cincinnati.
The Padres already had a young first baseman on the roster. Anthony Rizzo had originally been acquired from the Red Sox in the Adrian Gonzalez deal and hit .331/.404/.652 with 26 home runs in 94 games at Triple-A Tucson in 2011 at age 21. But he struggled mightily in a midseason call-up to the big leagues, batting .141 with one home run in 128 at-bats.
The Padres had a decision to make. Which first baseman to keep? They chose wrong.
Three weeks after acquiring Alonso, Byrnes made another deal: He traded Rizzo the Cubs for Andrew Cashner, a good old-fashioned challenge trade with two young players. Cashner has had his good moments with the Padres, but has also battled some minor injuries and had a rough 2015 in which he posted a 4.34 ERA. He's been worth 3.2 WAR with the Padres. Rizzo, meanwhile, has blossomed into one of the best players in the National League and finished 10th and fourth in the MVP voting the past two seasons, accumulating 16.3 total WAR since the trade.
The GM of the Padres when they acquired Rizzo? Jed Hoyer, who was working with the Red Sox when they drafted Rizzo. The GM of the Cubs (under president Theo Epstein) who traded for Rizzo? Hoyer. So he's acquired Rizzo three different times.
In retrospect, it's easy to say that Hoyer and the Cubs simply loved Rizzo. The minor league numbers, however, suggested Rizzo had superstar written all over him, crushing Triple-A pitching at a young age. Yes, his short stint with the Padres had been a disaster, but Hoyer said the Padres had simply rushed Rizzo too quickly to the big leagues. Byrnes made clear that trading Rizzo was a direct result of acquiring Alonso. "The acquisition of Yonder Alonso provided us the flexibility to make this trade and acquire a quality, young power arm in Andrew Cashner," he said at the time. Was Rizzo's poor performance in the majors a factor? Perhaps.
Alonso's minor league numbers suggested pedestrian power -- especially since he was three years older than Rizzo -- and that's been the case, as he has just 32 career home runs. He's also been unable to stay on the field, averaging 95 games the past three seasons.
There are many reasons why the Cubs are now where they are and the Padres are still where they are, and the Alonso/Rizzo decision is one of the biggest reasons.