It’s time to move on. Get over it. Forget about the amount of money Alex Rodriguez will be making. It’s none of your business. Even before Babe Ruth first tried to leverage with the Yankees for an unthinkable $100,000 salary back in the 1920s, a ballplayer trying to make as much money as he can out of his limited time in the sun has been a subject for public opprobrium. When Joe DiMaggio held out for something more than $25,000 in 1938, Jacob Ruppert, the owner at the time, told the public, “DiMaggio is an ungrateful young man, and is very unfair to his teammates, to say the least” — and the public bought it. When DiMaggio finally gave in, boos rained down on his every at bat. It wasn’t until his big hitting streak in 1941 that DiMaggio’s reputation recovered and his apotheosis into the “greatest living ballplayer” began. The dollar figures change, but the story does not.

Nor should anyone feel that the Yankees caved in some way, that Rodriguez got the better of them, or that Hank Steinbrenner is soft-headed or soft-hearted. We can’t assume that businessmen run their businesses rationally or with foresight — just look at the subprime mortgage crisis for evidence of that. But it seems likely that the Yankees know if they can afford the freight, and can also project how they might benefit from the signing based on how they already have benefited from having Rodriguez these last four years — in ticket sales (the Yankees have set a new high in attendance each year of the third baseman’s tenure), in merchandise and other licenses, and in revenues from YES.

If someday it proves to be the case that the Yankees could not absorb Rodriguez’s demands, if they become insolvent and go through a Florida Marlins-esque period and sell off their veterans, we can all laugh about how foolishly the Steinbrenners tossed away the game’s most lucrative franchise on one egomaniacal player. Until then, we need not care. If Rodriguez plays well, he’ll be worth whatever he’s getting within the range of huge, gross national products’ worth of money. If he hits .220, grows fat, misses endless games with injuries, then he won’t be. But to try to draw lines within the amount of money he’s getting and say, “Well, he hit .290 with 30 home runs, so that was worth $20 million but not a penny more” is a pedantic, pointless exercise. It would be like trying to decide whether A-Rod would be worth all the angels that fit on the head of a pin if he hit 40 home runs a year, or all the angels plus one if he hit 50. It’s a large amount of money no matter how you slice it, and unless you sign your checks with the name “Steinbrenner,” it shouldn’t matter at all.

What does matter is performance on the field, and whether Rodriguez’s elephantine payday will prevent the Yankees from spending the additional monies necessary to surround him with a winning cast as no one player, no matter how good, can drive a weak team to the playoffs. (Babe Ruth took plenty of Octobers off, and so did Ted Williams and — juiced or not — Barry Bonds.) We would expect this would not be the case, as it supposedly was with Rodriguez’s previous employer, the Texas Rangers. We would expect, though, that the Yankees ownership would understand that nothing correlates with attendance and other revenues like winning. Stars may sell a thousand extra seats. Winning sells hundreds of thousands. Again, if the Yankees have acted against their own self-interest and bought themselves a decade of A-Rod breaking records on 72–90 teams, the money becomes important — not because of Rodriguez’s greed, but because of the team’s folly in giving it to him.

Obviously the Yankees won’t get 10 more years like 2007 out of Rodriguez. Not only is Rodriguez not consistent at that level, but he’s also 32, no longer young in baseball terms. In the next few years, his ability to hit for average is going to go, probably at roughly the same time as his speed. He’ll walk a little more, strikeout a little more. His defense, already far from Robinson-ian (Brooks, that is), will decay, perhaps necessitating a move to first base. Fortunately, Rodriguez should continue to hit for enough power that he’ll be an asset across the diamond, especially by the standards of recent Yankees first basemen. As to whether Rodriguez will help them win a World Series or not, he probably will at some point — but maybe he won’t. The Yankees have won World Series with stars that were hot and won with stars that were cold. It’s a team effort. If A-Rod hits and no one follows him, the Yankees will probably lose in the playoffs. If he doesn’t hit and no one picks him up, as has happened the last few years — well, we know how that works out.

Until any of these things come to pass, and are proved to be true or untrue, we can’t put a real valuation on A-Rod’s salary, or say with any meaning whether it’s too high or too low. All the words spilled about the contract amount to nothing more than a kind of voyeurism directed at the man with the biggest deal.

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