When that happens, there is a protocol that is followed in choosing the replacement All-Stars.
Managers -- in this case, Leyland and National League manager Bruce Bochy -- get to replace the fan-elected starters who can't play, and also players whom they selected.
Position players elected by the player ballot, for the most part, are replaced by the next highest on the player ballot who isn't already an All-Star.
A fan-elected starter who can't participate is replaced in the starting lineup by the highest-ranking player ballot choice at the position who is not already starting.
Pitchers who start the Sunday before the All-Star Game are no longer automatically ineligible, a rule that was recently changed. They can still not pitch in the All-Star Game and be replaced on the roster. They also have the option of pitching a maximum of one inning, or they can pitch under a designated pitch count established beforehand, again with a one-inning maximum.
Pitching replacements are largely up to the manager.
As Leyland said, nobody likes to see All-Stars who can't perform because of an injury. But it usually happens, so there is a designated system to name the players who step in.
Paul Hagen is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.