Even the happiest married man or woman occasionally thinks back on the road not taken, the intriguing relationship that didn’t work out, the girl or boy who provoked a different — though not necessarily better — emotional response than one’s spouse. The same thing is probably true of that subset of humanity known as general managers, who must reflect not only on lost romance but on lost players as well.

Most of the time we can only speculate on what might have been. In baseball, life offers some broad hints as to what you gave up. Brian Cashman and pals are probably too wrapped up in the day-to-day of the 2006 season to reconsider old calls, but when the year ends they may have cause to look back and wonder about what might have been had they pursued some of the options they were offered.

During the off-season, two big-name, down-on-their-luck free agents rapped on the Yankee Stadium door looking for employment.Both had formerly been associated with the team’s biggest rivals. Defrocked shortstop and ex-Red Sox Nomar Garciaparra was the only remaining member of the so-called “Holy Trinity” of shortstops not in the Yankees’ possession after the acquisition of Alex Rodriguez paired him with Derek Jeter. Injury-plagued as always, Garciaparra had not only missed a great deal of time, but had lost a step in the field, forcing a move to third base. In 105 games with the Chicago Cubs spanning a season and a half, Garciaparra had hit just .289 AVG/.339 OBA/.453 SLG, a far cry from his batting title days in Boston and his .323/.370/.553 career rates.

The Yankees didn’t need a shortstop or a third baseman, but they did need a reserve who could play first base, DH, or even take an emergency turn in the outfield — things that Garciaparra was willing to do. Even with another .372 season (Garciaparra’s league-leading average in 2000) unlikely, it wasn’t a stretch to project that he would be more productive than Bernie Williams or Andy Phillips, the players in line for playing time at those positions. Even if his his bat might have been below average for a starter, it would have been above-average for a reserve.

In other words, Garciaparra’s willingness to play where needed would have meant that the Yankees could have avoided resorting to fringe players like Nick Green and Terrence Long in an emergency. Replacement-level players can severely damage a team’s chances when used for any appreciable length of time and are suicide in a close race.

The Yankees passed and Garciaparra signed with the Dodgers.Though he did suffer the inevitable injury, it came early and was mercifully brief. As the Dodgers’ everyday first baseman, “Nomah” has proved to be far from washed up, batting .346/.414/.571 with 25 doubles and 58 runs.

If carried over the full season, Garciaparra’s average would be the secondhighest in Los Angeles Dodgers history, trailing only Mike Piazza’s .362 average of 1997. Piazza was the other free agent who asked to become a Yankee, having been discarded by the Mets after very similar 2004 and 2005 seasons (.259/.345/.448 over the two seasons) suggested his best days were behind him at 36.This assessment missed a key fact: that a .793 OPS is still quite good for a catcher.

With Jorge Posada on hand, the Yankees didn’t need a starting catcher, but they did need a quality reserve. After his off-season in 2005, it appeared Posada would need increased protection from the rigors of catching. Even when considered as a diminished asset, Posada was still far superior to most catchers as a hitter. When he was out of the lineup, be it for injury, automatic daygame-after-night-game respites, or prophylactic days off, the offense was terribly diminished.

Having another catcher who could hit — and compared to the class of reserve backstops, Piazza’s continued vitality was even more apparent — would have mitigated this problem. Piazza also projected as a better hitter than Phillips or Williams, and could have taken up some slack at DH and been given as much or as little rest as he required. He also had a season’s experience of playing at first base (albeit not well). In all, a 350 at-bat Piazza promised to be a more valuable player than a 500 at-bat Piazza had been for the Mets.

The Yankees demurred and Piazza passed on to the San Diego Padres. The Pads don’t have the luxury of using Piazza as a DH, but otherwise have rationed his playing time, alternating him and two other catchers (at first Doug Mirabelli and Rob Bowen, now Josh Bard and Bowen). Piazza has responded with something of a comeback season, hitting .295/.352/.527 with 14 home runs in 237 at bats. His campaign is all the more impressive given the difficulties of hitting in San Diego’s Petco Park; Piazza is hitting .244/.319/.496 at home, but a fairer appreciation of his resurgence can be gleaned by looking at his performance in neutral parks, where he’s hitting a vintage-Piazza .347/.389/.559.

During his reign in the Bronx, Joe Torre has consistently favored a punchless, defense-only backstop as his reserve catcher. The Yankees have paid a repeated price for the predilection, and may yet again if Kelly Stinnett is called upon to play for any length of time.Stinnett’s supposed rapport with Randy Johnson has hardly benefited the team, and he’s been a disaster at the plate, as near an automatic strikeout as any player on the team.

Either Garciaparra, Piazza, or both would have insulated the Yankees from their greatest weakness: lack of depth on the major league bench and at the minor league level, and that’s without either being an outfielder, where the team is at its thinnest.Whatever factors the Yankees considered when passing on the two former All-Stars, whatever priorities they had in mind, shielding the team from injury wasn’t one of them. They gambled on their starters being invulnerable and lost.

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