Saturday's semifinal between the USA and Costa Rica will be a rematch of the game the Ticos won, 4-0, in November 2016,
but it will also set up an even bigger meeting Sept. 1 in World Cup 2018 qualifying.
The USA was in last place, four points out of third place after its loss at Costa Rica that cost Jurgen Klinsmann his job. Since Arena took over, the USA has gone unbeaten in four qualifiers, moving into third place, a point ahead of Panama -- and a swing of five points.
SCOUTING REPORT. Neither team will be at full strength. The USA will be without all its first-line players based in Europe, while Costa Rica's team has been depleted by injuries.
NYCFC's Ronald Matarrita withdrew from the Gold Cup before it started with a broken foot. Joel Campbell and Johan Venegas were among four players who withdrew because of injuries after the first round and Rodney Wallace was injured in the 1-0 quarterfinal win over Panama.
Still it is a sold team featuring Vancouver Whitecaps center back Kendall Waston in the back and Bryan Ruiz leading the attack.
USA vs. Costa Rica (Arena years):
2000: Costa Rica 2 USA 1 (WCQ)
2000: USA 0 Costa Rica 0 (WCQ)
2001: USA 1 Costa Rica 0 (WCQ)
2001: Costa Rica 2 USA 0 (WCQ)
2002: USA 2 Costa Rica 0 (Gold Cup)
2003: USA 3 Costa Rica 2 (Gold Cup)
2005: USA 3 Costa Rica 0 (WCQ)
2005: USA 0 Costa Rica 0 (Gold Cup)
2005: Costa Rica 3 USA 0 (WCQ)
Trivia: The 9 games (4 wins, 3 losses, 2 ties) are the most the USA under Bruce Arena has played against any team except Mexico (12).
LESSONS FROM WEDNESDAY. Arena said he thought some of his players, including five starters who had joined the team for the knockout stage, looked tired in the 2-0 win over El Salvador, where goals late the first half from Omar Gonzalez and Eric Lichaj decided the game.
For the first 30 minutes and in the second half, the USA simply did not look sharp.
"Our timing wasn't good," Arena said. "We didn't do well with the physicality. The game had no rhythm with all the fouls and players falling on the ground. But we weren't good on top of it. It took us 30 minutes to play a little bit. Then we got a little bit more assertive in different positions on the field, and capitalized on a couple of their mistakes. But it was just a sloppy game overall."
Arena said the USA has to do better, especially in attack.
"I told the team afterwards," he said, "I just thought it was some simple things. Our passing wasn't good. We didn't hold the ball up well enough. We didn't move well enough off the ball. We have to be a little bit better."
BIG PICTURE. A lot of questions were raised about some of Arena's lineup choices against El Salvador, he did get to look at four players who had not started in the Hexagonal: Matt Hedges, Justin Morrow, Eric Lichaj and Gyasi Zardes.
Even without his nucleus of European-based players, Arena has been able to start 27 different players in four games at the Gold Cup.
“I think one of the things we’ve benefited from in the tournament," he said, "was that we have been able to look at a lot of players and see how they fit in the big picture. If there is anything I get out of the Gold Cup, it's going to be that."