Imagine looking in your pocket and finding 10% of your yearly salary. It’s a lot more fun to imagine than the soggy $5 bill we usually find after laundry day. Baseball teams could do this, if they only knew which pocket to look in. In fact, the average team could do better than 10%. How? By reducing injuries.

Injuries have often been considered the result of bad luck or “part of the game,” as many of baseball’s unwritten rules are labeled. At Baseball Prospectus, the analytical minds have successfully challenged many of those rules — some hold up under scrutiny, giving us new insight into baseball wisdom, while others fall apart on closer inspection. Of course, injuries can never be completely eliminated, but they can be reduced. Injuries can decimate a low-budget team such as the Nationals, who have had to live with 21% of their total payroll going to players on the shelf, and even the least-injured team in the majors at the All-Star break, the San Francisco Giants, have lost “only” $1.6 million. For notoriously penny-pinching owners, these losses are no small thing.

Old-timers usually accuse the modern baseball player of being softer, but in fact, he is simply more precious: Players are no more fragile, their workload no lighter, and they are far less replaceable in the expansion and free-agent era. In an age when talent is so hard to come by, there are few if any players who get stuck in the minors, though, and sometimes teams can find lightning in a bottle, as the A’s did with Jack Cust. Although the number of days lost to the Disabled List has steadily increased throughout the free-agent era, it has grown in proportion to salary and in lockstep with the increased capacity of sports medicine to rebuild the ones the game has broken.

New York teams have seen significant injuries this season and in turn have lost significant production and payroll to the Disabled List. Both teams have lost nearly $17 million apiece. That’s nearly 15% of the Mets’ payroll; the loss comprises a lower percentage of the Yankees’ payroll, but it’s clear that the team had less depth to contend with “injury stacking” (a series of injuries at the same position), including the multiple pitching injuries in the Bronx, or the seemingly cursed left-field slot in Queens. It’s hard to blame Ray Ramirez or Gene Monahan and their staffers for this (though the Yankees did hold their former strength and conditioning coach accountable for a series of early-season hamstring injuries). However, there’s evidence not only that injuries and the ensuing monetary loss can be reduced, it’s actually relatively easy.

The Giants may not be leading the NL West, but they do get what they pay for. Almost all of the money the team has lost has been because of an injury to pitcher Russ Ortiz, who has been replaced by rookie Tim Lincecum. The Giants’ medical staff is led by first-year trainer Dave Groeschner, though much of the credit for the team’s injury statistics must go to former trainer Stan Conte, who is now the head trainer for the Los Angeles Dodgers. With a creaky roster full of old and injury-prone players such as Barry Bonds, Ray Durham, and Matt Morris, Groeschner and his staff are giving the Giants a better chance to compete.

Nevertheless, most teams appear to be willing to spend millions for players, while remaining oblivious to the money lost to the Disabled List. Training staffs of two are the industry standard, and a team’s medical budget is seldom more than $1 million, even factoring in health insurance and worker’s compensation premiums, expensive imaging such as MRIs, and the salary of athletic trainers, which is generally in the very low six figures. In a study conducted by Tom Gorman for “Baseball Prospectus 2006,” it was shown that the best medical staffs could save well above $5 million more than the average team’s loss — and add between three and four wins on the field. That’s like getting two better-than-average players at no additional cost. Still, few teams are willing to be creative or bring aboard additional staff to help with preventative care, to reduce the crushing workload on a two-man team that has to take care of 25 or more players, or to recruit those proven to be the best.

“I once asked if I could have 1% of the money I saved them,” the head athletic trainer for the Giants for 15 years, Stan Conte, said of team officials in a 2003 interview. “They didn’t like that idea.” The Dodgers decision last year to hire Conte might be on the cutting edge of a wider recognition of the difference a quality trainer makes. Los Angeles is anticipating the same results the Diamondbacks did in the first year after hiring head trainer Ken Crenshaw away from the Devil Rays on the heels of being named the game’s top trainer. Crenshaw reduced the D’backs’ salary loss by half in his first year, an immediate $3 million gain. Although the Dodgers aren’t on pace for such a dramatic cut, the team has seen gains in both its bottom line and a more important spot — the standings.

It might not be as sexy as signing an Alex Rodriguez or a Carlos Beltran, but a relative unknown such as a team’s trainer can make almost as big a difference, at a fraction of the cost. And although most fans couldn’t name even the head trainer of their favorite team, that man is hard at work, trying to keep his team on the field and at the top of the standings.

Mr. Carroll is a writer for Baseball Prospectus. For more state-of-the-art commentary, visit baseballprospectus.com.