Injuries naturally whittled the pitching pool a bit. The former All-Star Sonny Gray, who dealt with trapezius and forearm injuries last season, was denied a spot by the event’s insurance carrier. Max Scherzer, a two-time Cy Young Award winner, backed out with a finger injury.

Yet it is startling to consider how many healthy American starters will not be going. Besides Kershaw, Bumgarner, Kluber, Syndergaard and Verlander, there are Jake Arrieta, Zack Greinke, Cole Hamels, Kyle Hendricks, Jon Lester, Rick Porcello, Chris Sale and Aaron Sanchez. That’s 13 healthy, ace-level pitchers who won’t be there.

The fragile nature of pitching distinguishes baseball from every other sport. The pitcher has extraordinary influence on the outcome of a game, yet his task is so physically demanding that his workload is severely restricted. You can swing a bat as much as you want, but throw too hard, too often, and you’ll wind up in surgery.

This is why teams cringe when their pitchers take part in the W.B.C. The tournament is a joint venture between M.L.B. and the players’ union, leaving general managers out of the equation; they offer a thin smile, grit their teeth and go along. Expanding the game on a global scale is not their concern. Paid to build a team that can win the World Series, they shudder to see their pitchers exerting themselves in March for a different purpose.

This is why Verlander, who rediscovered his top form last season after dealing with a core injury, is out. He would like to pitch, but Jim Leyland, the manager for the United States and Verlander’s former manager with Detroit, advised him against it. On a human level, Leyland understands it is most important for Verlander to stay in his comfort zone as he prepares for the Tigers’ season.

That explanation makes perfect sense; Verlander earns an average of $28 million a year to win games for the Tigers. Kershaw, who was injured for much of last season, makes even more to do so for the Los Angeles Dodgers. Trout has no health concerns; he simply declined for personal reasons. In weighing his options last year, Harper bluntly said he did not sense much excitement from other stars.