Frankly, it's the only reason to even consider debating which slugging free-agent first baseman would be the better investment.
Both will break the bank this offseason, and some -- including colleague Anthony Castrovince -- say it's the 27-year-old Fielder they prefer over the 31-year-old Pujols, mainly because of those numbers residing in front of their names.
There's no question that both can elevate any team to a new level. But only one of them is a once-in-a-lifetime talent -- and the fact you already know who that is says it all.
Pujols should be priority No. 1, regardless of age. He's so good that the beginning of his decline -- and I don't believe he's there just yet -- may be better than the apex of Fielder's career, so good that he can stall the aging process a few years, and so good that when his new contract is reaching its end, which team signs him may even benefit financially from all the milestones he'll reach.
See, it's not just that Pujols is better than Fielder. It's that Pujols is much better than Fielder. Has been, and should continue to be.
Never mind the three National League MVPs or the 10 straight seasons topping a .300 batting average, 30 homers and 100 RBIs (two feats Fielder has never accomplished). Just look at the numbers since Fielder's first full season.
Pujols from 2006-11: .325 batting average (second in the Majors during that time), .424 on-base percentage (first), .613 slugging percentage (first), 244 homers (second), 708 RBIs (second) and a 47.5 Wins Above Replacement (first).
Fielder from 2006-11: .282 batting average (tied for 71st), .391 on-base percentage (11th), .541 slugging percentage (12th), 228 homers (third), 646 RBIs (sixth) and a 23.3 WAR (33rd).
Great? Absolutely. But Fielder is a distant second in this race.
Pujols is also worlds better defensively and doesn't have the drastic lefty-righty splits Fielder possessed every year before this one.
And then there are the things that stats don't measure, like Pujols' leadership and work ethic, both of which he displayed down the stretch of the Cardinals' championship season.
Like in July, when he came back from a fractured wrist far quicker than anyone could have imagined. Or in Game 4 of the Division Series, when he instinctively came off the bag to field Rafael Furcal's throw and gunned down Chase Utley before he could reach third base. Or in Game 3 of the World Series, when Pujols put up an unprecedented five-hit, three-homer, six-RBI performance.
"He's the best player in the game," Rangers outfielder Nelson Cruz said that night. "If anybody is going to do that, it's him."
This wasn't even a debate until Fielder's offensive numbers in 2011 (.299/.415/.566, 38 homers and 120 RBIs) edged out those of Pujols (.299/.366/.541, 37 homers and 99 RBIs).
Pujols' numbers were still great, and had it not been for those 50 extra plate appearances Fielder got with runners in scoring position, they may have been almost identical to the ones by the pudgy first baseman in Milwaukee. But considering his age and what he's done over the previous decade, some may have chalked 2011 up as the beginning of Pujols' decline.
They might want to take a closer look.
Despite the wrist injury, Pujols batted .318 with 28 homers -- topping the .305 average and 27 homers by Fielder -- from the start of June until the end of September, when every game mattered for the uphill-climbing Cardinals. Then Pujols proceeded to rake in the playoffs, batting .353 with a 1.155 OPS and five home runs in the 18 games that won him his second World Series title.
Does that seem like the beginning of a decline?
"Anyone who thinks that man is starting to fade," teammate Lance Berkman said during the Fall Classic, "is just plain crazy."
If I were running anything but a team with one of baseball's largest wallets, I wouldn't want either of these two. In a sport in which one player -- even one as special as Fielder or Pujols -- can't significantly alter wins and losses, it's hard to justify him absorbing a quarter of a team's payroll for the next decade. And if the average annual value of their contracts is $25 million -- a very obtainable number for both -- that's what Pujols and Fielder would have done on 18 of the Major Leagues' 30 teams last season.
But aside from that, what is relevant is that whoever signs Pujols and Fielder basically has to understand that they'll be overpaying when the contract begins reaching its final stages and their careers do the same. It's a reality clubs must come to grips with when giving a free agent a historic deal like the ones these two will nab.
So, it all boils down to one question: Which of these two will provide the most value in return?
Pujols is the answer. History and trends may suggest he'll reach the twilight of his career faster than Fielder, and thus won't supply as much bang for the buck. But nothing about Pujols -- not anything he's ever done in his 11 years in the Majors -- would suggest he's in any way similar to any player who came before him.
In this free-agent class, Pujols is king and Prince is, well, prince.
Four years, three months and 23 days simply isn't enough to close that gap.
Alden Gonzalez is a reporter for MLB.com. Read his columns and his blog, listen to his podcast and follow him on Twitter. This story was not subject to the approval of Major League Baseball or its clubs.