The Yankees have been candid about Mike Mussina’s groin injury. It’s not serious. Under normal circumstances you might see the wounded Moose gut it out, but having a 6.5 game lead in late August affords a team some luxuries. While it would be inadvisable for Joe Torre to hang a “Mission Accomplished” banner over the home dugout and start walking around in his flight suit — and that’s not a political analogy: Manager Tom Runnells of the Expos did something very similar in 1992. In the long history of baseball, everything has been tried at least once — but the Yankees are all but a certainty to win their division. Baseball Prospectus’ postseason odds report gives the Yankees a 98% chance of making it.

As such, the Yankees can risk another start or two on Jeff Karstens, a fly ball-inducing rookie with questionable stuff whose rotation spot — having already brought him into contact with the Mariners — will, sequentially, see him facing the Angels, Twins, and Royals. These are the four offenses in the American League least likely to hit a home run, in descending order. This is either a fortuitous coincidence or one of the best examples of planning in the history of sport.

Speaking of planning, as Mike Mussina told MLB.com yesterday, “Why not take the extra time, get some help up here right now and make sure this doesn’t come back to haunt us in the middle of next month, when we can’t afford it.” Indeed. It’s the baseball equivalent of pulling your quarterback at halftime after you’ve already clinched a first-round bye. This is an old strategy and at least once it paid off in a World Series win.

It’s one of the most oft-told tales in baseball. In 1929, Connie Mack’s Philadelphia A’s had locked up the pennant by the middle of June. At the back end of the pitching staff was a perpetually sore-armed 35-year-old right-hander, Howard Ehmke. He was a strange pitcher. Ehmke was tall for the day, extremely thin, and threw sidearm with control that varied from middling to excellent.Though Ehmke pitched for some poor teams, the results were generally quite good. By his mid-30s he was getting by on deception rather than stuff.

That’s when Ehmke was healthy. Mack got all of 11 appearances out of him in 1929, and though Ehmke won seven of those games, by August Mack figured he no longer needed to nursemaid the veteran. He called Ehmke into his office and told him he was letting him go.

Ehmke begged to stay on. He had never pitched in a World Series and wanted this last chance. “I think I’ve got one more good game in there,” he said of his arm. Mack thought it over, and what Bill James later called the most brilliant managerial stratagem in the history of baseball came to mind. Mack didn’t release Ehmke, but he also didn’t keep him with the team. The Chicago Cubs had also wrapped up the pennant early so the World Series match-up was a foregone conclusion. In the middle of the month, the Cubs would visit Brooklyn, New York, and Philadelphia. The A’s left town for a western road trip. Ehmke stayed, rested his arm, and took in all of those Cubs games.

The A’s had two 20-game winners that year, George Earnshaw and Lefty Grove, the latter of whom had already established himself as the best pitcher in baseball. No manager in baseball, before or since, would expose himself to second-guessing by not pitching one of his two aces in the opening game of the World Series at Chicago. Mack, who had already been in the game for over 40 years and had seen everything (except for Tom Runnells in full military regalia), named Ehmke as his starter.

The result of Mack’s gambit have never lost their place in World Series lore.The Cubs had a terrific lineup that year, with three future Hall of Famers — Rogers Hornsby, Hack Wilson, and Kiki Cuyler. Ehmke neutered them. In a nine inning complete game, Ehmke scattered eight hits while striking out 13, a high total for the time (Cubs batters averaged about four strikeouts per game that year) and didn’t allow a run until the ninth inning, when an error forced an unearned run to score. The A’s won the game and went on to take the Series in five.

Mike Mussina won’t be given the rest of the season off, as Ehmke was, and with the advent of the playoff system, there is no way of knowing which teams will appear in the World Series. Nor is there any benefit that he’ll dominate anyone in any of his postseason starts. Yet, the beneficial aspects of this little vacation should be about the same. The Yankees’ most consistent pitcher this season, Mussina is also 37 years old and as the last two seasons have shown, not nearly as durable as he was in his prime.

The same goes double for Randy Johnson. Johnson has swung from ace to goat this year, and the pendulum rocked particularly fast after Torre let him throw 129 pitches against the Mariners on July 19. Whereas Johnson used to have a seemingly endless number of bullets in his gun, now a hard night’s work fatigues him for longer than the next four days.

After Mussina returns from his time away, the Yankees should see if they can contrive to get the same kind of break for the Big Unit. With careful handling of the pitching staff, the ghost of Howard Ehmke might just possess someone in pinstripes this year.

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