The Gold Cup has long been a tale of two tournaments for the U.S. national team.

First there’s the group stage. With every team guaranteed three games, there’s plenty of margin for error — though the U.S. has rarely needed that, winning its group 13 times in 14 tournaments and losing just once in 37 group-play games since 1991.

Then there’s the unforgiving knockout stage, where one mistake can ruin everything. That happened two years ago, when losses to Jamaica and Panama left the Americans out of the title game for the first time since 2003.

“It gets real,” Landon Donovan, a former Galaxy forward who played in six Gold Cups for the U.S., said of the elimination rounds. “If you have a bad day, the tournament’s over.


“So once the knockout stage comes, the mentality changes.”

Sometimes the roster changes too, as it did this week with U.S. coach Bruce Arena calling up a half-dozen veterans ahead of Wednesday’s quarterfinal with El Salvador at Philadelphia’s Lincoln Financial Field (FS1, 6 p.m. PDT).

A pair of unbeaten teams meet in the first quarterfinal, with Group A champion Costa Rica facing Panama, the runner-up to the U.S. in Group B. (FS1, 3 p.m. PDT).

Teams are permitted six roster changes between the group stage and the knockout rounds, and Arena used the full allotment after his team cruised through the first round unbeaten. Among those sent home were midfielders Cristian Roldan and Kelyn Rowe and forward Dom Dwyer, none of whom has played in more than three international games.


In their place Arena summoned a group that includes Clint Dempsey and Tim Howard, who have both played in three World Cups.

“In the end, he wants to win the tournament,” Donovan said of Arena, his coach with both the Galaxy and the national team. “He accomplished everything he wanted. He won the group. Got to look at every [new] player in a real game. That’s all you can ask for.

“But there are other needs and other things Bruce wants to accomplish as he goes into these final games.”

Also joining the team are forward Jozy Altidore, goalkeeper Jesse Gonzalez and midfielders Michael Bradley and Darlington Nagbe, with the six players adding more than 500 games of international experience to the U.S. roster.


“Those guys come in and help us raise that bar to a new level,” said midfielder Chris Pontius, who is playing in his first Gold Cup. “The amount of caps, goals and just experience overall, that’s the biggest thing they bring.

“They just bring the group to a new level.”

Which is a good thing, since the competition has risen to a new level as well. Gone are French Guiana, Nicaragua and Curacao, none of which won a game, while of the eight teams remaining four — Mexico, Costa Rica, Honduras and the U.S. — played in the last World Cup. Three of the four advanced to the round of 16, with Costa Rica reaching the quarterfinals.

Tournament rules have changed as well. In group play, games that were even after 90 minutes ended in a draw. But in the quarterfinals and semifinals, ties will be broken in a penalty-kick shootout, a concession to the Gold Cup’s TV partners who don’t want 30-minute overtime periods muddying their broadcast schedules.


“Penalties make it a little more nervy,” said Donovan, who will serve as an analyst on Fox’s coverage of Wednesday’s game. “And Bruce knows that. That’s why he brought in the guys he brought in. There’s no room for error now.”

The winningest coach in Gold Cup history, Arena (16-1-4 in four tournaments, two of which he won) said he studied videotape of El Salvador and came away impressed. Then he had his team practice penalty kicks Tuesday morning, just in case.

“They’ve played some of the best football in the Gold Cup so far,” Arena said of the Central Americans, who finished third in their group after losing to Mexico, beating Curacao and playing Jamaica to a draw.

“They keep the ball on the ground. They’ve got good quickness in the attack. Their strikers are quality. Their wide players are very good. So they’re going to be a difficult team to play against.”


kevin.baxter@latimes.com

Twitter: kbaxter11