To the casual baseball fan, “Mientkiewicz” is simply an unpronounceable name that, if it has any meaning at all, inspires a greater appreciation for the art of uniform lettering: How do they squeeze all those letters onto one man’s back? For the Yankees, he represents something greater, a multimillion-dollar gamble on the outcome of their season.

Joe Torre has spent a good deal of the spring offering alibis for Doug Mientkiewicz’s poor offensive showing, something that he’ll likely be doing all season if Mientkiewicz retains his job as starting first baseman. Torre is besotted by his glove, as well he might be after years of watching pigeons alight on Jason Giambi’s shoulders. That experience, combined with Gary Sheffield’s fumblings in the postseason, have traumatized the Yankees. In signing Mientkiewicz, they’ve overcompensated. It’s understandable, but like a starving man who goes on an eating binge, there are likely to be consequences.

Then again, they might make history.

It’s hard to say who the worst first baseman in Yankees history is. It’s probably a toss-up between Johnny Sturm, a first baseman who momentarily caught manager Joe McCarthy’s eye in 1941, and Don Mattingly.

Before you march on The New York Sun’s offices, we’re not talking about that Don Mattingly, the MVP award winner with the Hall of Fame-level stats. We’re referring to his later incarnation, the one who had lost power and consistency to back problems. In 1990, Mattingly hit .256 AVG /.308 OBA/.335 SLG. Mattingly wasn’t the only reason the Yankees lost 95 games that season, but he was a big contributor.

The 2007 edition of the Yankees isn’t in any danger of losing 95 games, but they might not win 95, and it could take that many victories to conquer the AL East. For all the changes the Yankees and Red Sox have made this off-season, in spite of Daisuke Matsuzaka and Andy Pettitte, and all the other players who have changed the color of their laundry, the two teams are closely matched. While it’s impossible at this early date to know how many of each team’s carefully hatched plans will reach fruition, even allowing for a decent number of each team’s gambles to fail —Dustin Pedroia could fail to hit, Carl Pavano could get hurt again, or several times — the standings should be tight.

In a race that might be decided by a game or two, almost any random event can prove to be decisive. All it takes is a bad bounce of the ball in a mid-May game and you find yourself on the wrong side of the playoff line come October. You wouldn’t want to pick that season — the one that you’re not going to storm your way through like the 1927 Yankees —to offer your worst first base production of all time. The timing would be bad.

Despite a spring batting average that reached the lofty heights of .077 after Monday’s double and 2004–2006 rates of .253/.335/.386, the Yankees are prepared to allow Doug Mientkiewicz to be the long half of their first base platoon this season.

Last season, AL first basemen hit .280/.352/.467 and hit a home run once every 24 at bats. That’s exactly half of Mientkiewicz’s career home run rate. This is a man who can kill a contender dead. You score fewer runs, you win fewer games, and one of the easiest ways to score fewer runs is to put a limp bat at first.

Of course, as Joe Torre keeps saying, it’s not Mientkiewicz’s bat the Yankees want, it’s his glove. Mientkiewicz won a Gold Glove back in 2001, and apparently the Yankees haven’t updated their scouting reports since then. Mientkiewicz is five years older and has rolled over the odometer on his back. Sure, he still looks great compared with Jason Giambi, but even the Venus de Milo outshines him on the fielding job. The Yankees weren’t wrong to want to consign Giambi’s glove to the flames for all time, but they were wrong in the way they went about it.

There’s a secret about defense in baseball: You can actually count the number of plays available to each position. Only so many of those plays require a great glove; for most of them, the average fielder will serve. There’s no evidence to support the idea that the greatest defensive first basemen, say a Mattingly or Keith Hernandez at his peak, saved his team more than — let’s be outlandishly generous — 20 to 30 runs a year with their glove. Even if Mientkiewicz was half that good this year, and that’s unlikely, he’ll save 15 runs.

That still leaves the Yankees short. If the average first baseman puts 90 runs on the scoreboard with his bat over the course of the season, and Mientkiewicz only puts up 60, even giving him credit for his glove leaves the team at a deficit.

The Yankees do have alternatives. Unfortunately, all of them involve strangling the roster with extra first basemen. Andy Phillips is a 30-year-old “young” player with a below-average bat for a first sacker and, at least last year, a reverse platoon split. That means both ends of a Mientkiewicz/Phillips platoon could be a bust. Rule 5 pick Josh Phelps doesn’t have the defensive chops of either Mientkiewicz or Phillips, but can outhit both, particularly against southpaws. He’s the best pure offensive choice currently possessed by the Yankees, a batter who won’t hit for average but will send a fair number of balls over the wall.

Finally, there is always a possible return to Giambi, who for all of his defensive problems would free up the designated hitter spot for Melky Cabrera.

The Yankees say they can “carry” Mientkiewicz’s bat, but “carry” is code for giving away potential wins, but they don’t really know if that’s true or not. “Mientkiewicz” is the tune the Yankees play as they go whistling past the grave of their pennant hopes.

In the end, another bat, presumably carried by another player, will be the solution to the first-base problem. The Yankees are too smart to blow a postseason berth by playing a weak bat at first over a full season. When Mientkiewicz hits as he always has, the Yankees will claim to be surprised and disappointed, then pull the trigger on a deal for someone like Richie Sexson.

Mr. Goldman writes the Pinstriped Bible for www.yesnetwork.com and is the author of “Forging Genius,” a biography of Casey Stengel.