SAN ANTONIO — For nearly three decades, becoming the first-choice goalkeeper of the United States has been a bit like being appointed to the Supreme Court, so permanent is the tenure.

While the United States labors to earn a place among the world’s top national squads, producing quality keepers has never been a problem. But those keepers who are not No. 1 face a different challenge. They log the same hours on the practice field, but when a competitive match comes along, there rarely exists any doubt who will be picked to start between the posts.

“Some of it is just the nature of it; there’s only one,” said Kasey Keller, who had a long spell as the team’s No. 1 keeper during his 22-year career. “That can be a difficult aspect of it. It has nothing to do necessarily with your ability. It has to do with the person in front of you. If he continues to play well, why would a coach change it?”

Since 2007, that automatic selection has been Tim Howard, 36, who played every minute of the previous two World Cups and in almost every other important competitive game, save for brief instances in which he has been injured. Howard, who has played 104 official international games, only extended the tradition of stability on the goal line. Before him, there was Keller (101 international games), Brad Friedel (82) and Tony Meola (100), each one keeping a horde of talented countrymen on the sideline.