Not resigning Albert Pujols, 2011 offseason
Let's start off with one of the biggest "what-ifs" in Major League history. Albert Pujols was arguably on pace to be the best hitter in Major League history from his debut season in 2001 to his departure to the Los Angeles Angels in the 2011 offseason.
Pujols slashed .328/.421/.617 with 445 HR and 1329 RBI during his early stint with the Cardinals. He was a two-time World Series champion, three-time MVP, six-time silver slugger, two-time Gold Glover, and a nine-time All-Star. He was never the same after joining the Angels.
From 2012-2021, Pujols hit just .256/.311/.448 with 234 HR and 821 RBI while finishing 17th in MVP voting twice and going to one All-Star game. If you watched Pujols playing for the Angels, he just felt like a guy who wasn't very happy, and I can't help but wonder if he would have been a much better player had he remained in St. Louis.
Before trading for Paul Goldschmidt before the 2019 season, the Cardinals had names like Allen Craig, Matt Adams, Mark Reynolds, Brandon Moss, Jose Martinez, and Matt Carpenter playing first base for them. Although they likely don't end up with Goldschmidt if Pujols stays, you could for sure argue they get much more production from the position in 2012-2018.
Maybe the Cardinals win the World Series in 2013? Or maybe they get past the NLCS in 2012 or 2014? While we'll never know the answer to that, I know we are all glad Pujols got his reunion with the club during the 2022 season,