U.S. women's national soccer team head coach Vlatko Andonovski offered few clues on Tuesday about his highly anticipated Olympic squad, as the team prepares for a training camp and three-game Summer Series next month.

Twenty-three players, including veteran forwards Megan Rapinoe and Alex Morgan, and top defender Crystal Dunn, will travel to Texas for the trio of friendlies against Portugal, Jamaica and Nigeria, with the Tokyo Olympics less than two months away.

"The players that we chose for the most recent roster are the ones that we’re focusing the most on at this moment," Andonovski told reporters. "But nothing is closed until the roster is chosen."

The exhibition matches afford a final chance to stand out, with Andonovski expected to announce the 18 Tokyo-bound players days after the final June 16 friendly.

Three-time National Women's Soccer League champion Lynn Williams, who was overlooked for the 2019 World Cup-winning squad, and college phenomenon Catarina Macario are among those still in the running for their first-ever Olympic squad berths.

Andonovski said he hoped the Texas heat will help prepare players for sweltering summer conditions in Japan, where the United States will be out for revenge after Sweden knocked them out in the quarterfinals in Rio de Janeiro in 2016.

A notable omission from the Summer Series squad was two-time U.S. Soccer Female Player of the Year Julie Ertz, who suffered a knee ligament injury with the Chicago Red Stars in the first game of the NWSL season.

"She’ll be good and ready to play in our sendoff series," said Andonovski. "Right now, her progression is going well, she’s started back jogging but we’re going to be very careful in terms of how we approach her recovery."

The U.S. women's national soccer team faces Portugal on June 10 in Houston, Texas.