In economics, the term “sunk cost” refers to an expenditure which you cannot reverse no matter how much you might like to or how pointless the outlay proved to be.If you buy a fake Rolex on a street corner and the watch doesn’t fool anyone, there’s no returning that baby to the store. You might as well throw it in the trash, because no matter what you do you aren’t going to get value out of it.

Baseball teams encounter sunk costs all the time, but often shy away from facing them. In large part that’s because no general manager wants to tell his team’s owner that he’s invested $10 million or $15 million on a pitcher who can’t pitch or a hitter who can’t hit. Those players stay in the lineup, costing their teams money beyond even their salaries because in performing badly they push their team away from the postseason and its financial rewards.

The Yankees have two sunk costs on their pitching staff in the form of Carl Pavano and Jaret Wright. Pavano’s injuries mean that the decision to pitch him, sit him, or pay him to be someone else’s problem has been taken out of the team’s hands (Pavano’s recent exposure as the pitching Pinocchio may hasten efforts to deal him nonetheless).

Wright is a different matter.While he has had periods of effectiveness this season, they’ve been more a matter of good luck than pitching well. His control has been weak and batters have been right on his stuff; the percentage of batted balls allowed by Wright that were line drives is among the highest in baseball.

Wright also places an undue burden on one of most abused bullpens in baseball. Wright has pitched into the seventh inning once all season, and even then he retired only one batter in the frame (this was in his most recent start).With friends like this, Scott Proctor doesn’t need enemies.

Wright is signed through next season, but his value to the 2007 starting rotation is questionable. Prospects Tyler Clippard and Phil Hughes had very successful campaigns at Double-A Trenton (175 strikeouts in 166.1 innings with a 3.35 ERA for Clippard and 138 strikeouts in a carefully monitored 116 innings with a 2.25 ERA for Hughes), and should be ready to arrive in the Bronx early next season if not sooner. Darrel Rasner, who pitched well on Sunday, was considered a decent back-of-the-rotation prospect before his recent injury. Jeff Karstens has had the good fortune to pitch his three major league games against three of the worst offenses in the American League. He might not fare as well against deeper lineups, but he has shown enough that the Yankees should risk a game on finding out.

One of the benefits to the Yankees of having a nine-game lead with just 27 games to play is that they can afford to prepare for the playoffs while also building for the future; if the Yankees were to go 13–14 the rest of the way, the Red Sox would still have to win 22 of their remaining 25 games to beat them.

The way the Yankees lineup is currently structured, Wright is the fifth starter, following Chien-Ming Wang, Mike Mussina, Randy Johnson, and Cory Lidle. In the postseason, the fifth starter becomes a fifth wheel, pitching only in blowouts.Wright’s place will be in the bullpen, and the Yankees might as well put him there now. At the same time, Rasner and Karstens, who won’t pitch in the postseason at all, can continue making their cases to be on the 2007 staff or back in the minors.

This winter’s market for free-agent pitchers will be a weak one. There are few sure things, if any, and the competition will be fierce even for pitchers like Lidle, whose contract is up. Given the age and injury history of even the best pitchers, the Yankees could easily find themselves with another Pavano or Kevin Brown on their hands if they choose poorly.

The most sensible policy will be a conservative one, not overspending on rotation-filler when the Yankees may have that at home. Even if a Rasner or a Karstens is not the answer in the long term, they may suffice to hold the fort through April (the month with many friendly off-days allowing the fifth starter frequently to be skipped) until one of the top prospects is ready to fly.

The same, of course, could be said for Wright, who’s signed through next season. He, though, is a known commodity. The Yankees know that on any given day they might get six innings in which he dances between the raindrops. That’s not something you’d normally plan to build a staff around, especially given how 30 iterations of that could shred your bullpen all over again.

Wright’s current ERA is 4.62. That is, the healthy and effective Wright has been good enough to post an ERA about a tenth of a run higher than the league average. It seems likely that one of the youngsters might be able to give the Yankees roughly the same or better results. All the Yankees have to do is accept that Wright is a sunk cost, and move on.

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