European-based stars won't be present when the United States women's national team holds its first training camp since March, but Brazilian-born Catarina Macario's place on the field marks an important step in the emerging star's journey to represent her adopted country.

The national team will hold a 10-day camp in the Denver area beginning on Oct. 18. The U.S. has not gathered as a team since the SheBelieves Cup in March. The U.S. defeated England, Japan and Spain to win that tournament, which was completed days before the sports world shut down in response to the coronavirus pandemic.

The October camp will be held in a bubble-type environment similar to the NWSL Challenge Cup this summer. Players, coaches and staff will operate out of a hotel in the Denver area and be tested multiple times before arrival, upon arrival, and every two days during the camp.

"Getting the national team back together brings us relief and excitement, and I'm thankful for all the work done behind the scenes to make this happen, and make it happen safely for all the players and staff," U.S. coach Vlatko Andonovski said in a statement. "We're going to be smart and efficient in how we conduct this camp, but we know that the Olympics will be coming fast once the calendar turns to 2021, so we have to make as much progress as we can during the time we have in Denver."

That progress will have to be made without Tobin Heath, Rose Lavelle, Sam Mewis, Alex Morgan and Christen Press, the quintet of World Cup winners who signed with English teams in the Women's Super League teams this fall. With no U.S. games scheduled, their club teams were not obligated to release them for international duty and the travel and associated quarantine restrictions would have made their participation impractical regardless.

"For this camp, it just did not make sense for the players in Europe to leave their club environments, where they are getting quality training games, as they are just starting to get settled," Andonovski said. "But this opens up the important opportunity for other players to step up and show if they can contribute to the national team during our run to the Olympics."

Also missing from Andonovski's camp roster are Carli Lloyd, who has not played in the NWSL's limited fall schedule while recovering from an injury, and Megan Rapinoe, who opted out of the NWSL fall series. U.S. Soccer cited injury concerns on Rapinoe's part for her not traveling to Colorado. Neither Lloyd nor Rapinoe has played since the SheBelieves Cup.

A regular starter in the U.S. World Cup title run a year ago, midfielder Julie Ertz will not be part of the camp. Ertz, who also opted out of the NWSL fall series, cited a family commitment.

But in addition to the inclusion of many NWSL players who impressed during the limited opportunities available to U.S.-based players in a season reduced to the Challenge Cup and fall series, the roster includes Stanford senior Macario. Born in Brazil and still working through the application process for U.S. citizenship, she previously trained with the U.S. under-23 national team and played in several preseason exhibitions against NWSL teams.

The two-time reigning Hermann Trophy winner as college soccer's best player was a heavy favorite to become the first three-time winner of that award until the pandemic disrupted the college season. With 63 career goals, she entered this season as NCAA active leader by more than 20 goals. She also held a double-digit lead as the active leader in career assists.

Macario moved to the United States with her father and older brother when she was 11 years old to allow both children access to better educational and athletic opportunities. Their mother, a doctor, continues to live and work in Brazil. Macario has long stated a desire to play for the U.S.

FIFA recently amended its regulations for naturalized citizens seeking to represent their new country in competition. Previously, a naturalized citizen had to wait five years beyond their 18th birthday to play for their new national team unless they obtained a waiver from FIFA stipulating that, among other criteria, the player moved to the new country for non-football reasons. Danish international and former Portland Thorns forward Nadia Nadim received such a waiver after her family left Afghanistan when she was a child and sought asylum in Denmark.

The amended regulations change when the clock starts on the residency requirement. For someone like Macario, who moved to the United States as a minor (but after her 10th birthday), the five-year requirement is counted from the time of her arrival, as opposed to her 18th birthday. Thus Macario, who turned 21 earlier this month, will already meet FIFA's residency requirement once she becomes a U.S. citizen.

The other notable change in the FIFA regulations was in the wording related to approval from the organization. Previously, the waiver depended on the person moving to the new country for non-football reasons. The new regulations say only that a player should not have moved to a new country "for the purpose of participating for its representative teams," a more narrowly-drawn prohibition suggestive of direct recruitment by a soccer federation.

Macario, whose brother studied film at USC and who herself eschewed an opportunity taken by multiple teammates to leave Stanford early for professional soccer in order to complete her degree, already had a strong case that her move was for reasons beyond sport. The new FIFA regulations appear to make her eligibility all but a formality once she obtains citizenship.

Macario told ESPN earlier this fall that she still hopes to complete the citizenship process this year. Her application is caught in a pandemic-related backlog, but her paperwork is complete and she is awaiting word on when she will be allowed to take the citizenship test.

The training camp roster includes a number of players with national team experience who are looking to get back in the regular rotation, such as NWSL summer and fall standout Kristie Mewis of the Houston Dash. It also includes young players who may benefit from the extra year of development and auditions ahead of Olympic roster competition, such as Portland Thorns rookie Sophia Smith and Washington Spirit rookie Ashley Sanchez and current collegians Macario, Stanford defender Naomi Girma, UCLA forward Mia Fishel and Florida State midfielder Jaelin Howell.

Unlike some U.S. national teams, such as in softball, Andonovski had not named an Olympic roster prior to that event's postponement, so there is no issue of carrying over the same group of players to next summer.

USWNT October Training Camp Roster (Club/College; Caps/Goals)

GOALKEEPERS (4): Aubrey Bledsoe (Washington Spirit; 0), Jane Campbell (Houston Dash; 3), Ashlyn Harris (Orlando Pride; 25), Alyssa Naeher (Chicago Red Stars; 63)

DEFENDERS (10): Abby Dahlkemper (NC Courage; 61/0), Tierna Davidson (Chicago Red Stars; 26/1), Crystal Dunn (NC Courage; 104/24), Naomi Girma (Stanford; 0/0), Sarah Gorden (Chicago Red Stars; 0/0) Ali Krieger (Orlando Pride; 107/1), Kelley O'Hara (Utah Royals FC; 131/2), Margaret Purce (Sky Blue FC; 1/0), Becky Sauerbrunn (Portland Thorns FC; 177/0), Casey Short (Chicago Red Stars; 32/0)

MIDFIELDERS (7): Shea Groom (Houston Dash; 0/0), Lindsey Horan (Portland Thorns FC; 86/19), Morgan Gautrat (Chicago Red Stars; 87/8), Jaelin Howell (Florida State; 0/0), Catarina Macario (Stanford; 0/0), Kristie Mewis (Houston Dash; 15/1), Ashley Sanchez (Washington Spirit; 0/0)

FORWARDS (6): Bethany Balcer (OL Reign; 0/0), Mia Fishel (UCLA; 0/0), Ashley Hatch (Washington Spirit; 2/0), Sophia Smith (Portland Thorns FC; 0/0), Kealia Watt (Chicago Red Stars; 3/1), Lynn Williams (NC Courage; 28/9)