It’s been a great 24 hours for the Yankees and Brian Cashman. In adding Bobby Abreu and Cory Lidle, the Yankees have probably improved their team by two to three wins. It doesn’t sound like much, but with eight weeks left in the season and the race tight, three wins could be decisive.And if you like what a potential three extra wins can do in a tight race, imagine what four wins can do.

In trading Shawn Chacon to the Pirates for Craig Wilson yesterday, the Yankees did just that. Forget that Wilson is a good bat and a versatile player, or that the Yankees stole him in exchange for a damaged-goods pitcher for whom they had no more use. What’s more important is that his acquisition frees the Yankees to do something that will earn them an additional win all by itself: Bench Andy Phillips.

Despite a couple of hot streaks, Phillips’s overall rates of .239/.272/.401 have been devastatingly bad. Those numbers would hurt at any position but have been especially crippling at first, a position where above-average production is expected. National League shortstops are out-hitting Phillips, to say nothing of American League first basemen, who as a group are batting .273/.347/.458. The league as a whole is batting .275/.340/.437, so the Yankees have been doing opponents a big favor by giving regular playing time to a player who is about 15% less productive than average and 20% less productive than the typical first baseman.

Because Jason Giambi is such an abysmal fielder, the Yankees allowed themselves to tolerate Phillips’s soft work with the stick, but the overall results were equivalent to giving away a game in the standings for free. Those days are now over.

Or are they? Phillips will remain on the roster even with the addition of Wilson. “Andy’s on this team,” Brian Cashman said after the deal. “As we move forward right now, Andy Phillips is definitely a part of this team and Joe Torre will have decisions to make on a daily basis on how he wants to attack his opponent. I think the match-ups will dictate what Joe decides to do.”

It’s not clear how we’re supposed to translate that, because Phillips would seem not to have a clear role at this point. Since he only plays second and third base in emergency situations, he’s not a utility infielder. He’s a slow, right-handed, non-hitting first baseman. Wilson, a career .268/.360/.486 hitter, is by far the superior bat. Like Phillips, Wilson is right-handed, so there’s no possibility of a platoon. In fact, Wilson is at his best against southpaws (.302/.404/.556 career), while Phillips has struggled against them (.195/.245/.247 this season).

The only area in which Phillips exceeds Wilson is defense.The Pirates had Wilson in the majors for six years and in the minors for six years before that, but because the Pirates are very, very good at being very, very bad, 12 years didn’t give them enough time to settle on a position for him. He can play first base, right field, and catch, but he’s not going to ever win a Gold Glove, or even a Gold Foil-with-Chocolate-Inside Glove.

Over the years the Yankees have worried disproportionately about defense at first base and not enough about shortstop or the outfield, and keeping Phillips around would seem to be another example of their mania.Torre will now be free to start Phillips when groundballer Chien-Ming Wang pitches, or when a lefty is on the mound, or if it’s overly humid, or because he sees a batter-pitcher match-up he likes (given Phillips’s short career that kind of data is going to be meaningless). Chances are, the return won’t be worth the trouble.

The retention of Phillips is also illustrative of the way the Yankees can get sentimentally attached to certain players regardless of their quality. Contrast this with the Tigers who, in acquiring Sean Casey earlier today, unceremoniously sent Chris Shelton to Toledo.Shelton played 103 games for the Tigers this year, and 237 games over the last three. On a first-place team, this would normally earn a player tenure: “Don’t mess with success,” “We’ve gotta go with the guys who got us here,” or “You dance with the one that brung ya.” These are all time-tested baseball excuses for standing pat. The Tigers, in a hurry to win something after nearly 20 years in the wilderness, aren’t allowing themselves that luxury.

The Yankees apparently feel less urgency about things, because the decision to retain Phillips has twisted their bench into a ghastly shape. Aaron Guiel, their best bet for a lefty power threat off the bench, was sent down rather than the now-redundant Phillips.Bernie Williams can no longer hit left-handers and Bubba Crosby, another player without a clear role, can’t hit any-handers, so the Yankees will be weak in the pinch-hitting department for the time being — something that will be a problem for as long as Miguel Cairo plays for Robinson Cano or whenever Sal Fasano substitutes for Jorge Posada.

These would seem like minor considerations, but even with the addition of Cory Lidle (who need merely pitch to an ERA somewhere below 8.00 to be better than the pitchers he’s replacing), Yankees pitching is still going to be shaky. The offense will have to exploit every opportunity to score in order for the team to survive. Then, if they reach the postseason, the bench becomes even more important. In 2001, Torre and Cashman took a punchless bench of Clay Bellinger, Todd Greene, Luis Sojo, Enrique Wilson, and Randy Velarde to Arizona and lost the World Series because of it; a bench of Williams, Fasano, Crosby, Phillips, and Cairo (assuming Cano returns) would be just as impotent.

But let’s not lose the forest for the trees.This is a day of celebration for the Yankees. They picked up three major pieces, improved themselves all over the field, and gave away very little value in the process. They’ve put themselves in the position to win.

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