The U.S. will kick off 2019 with a pair of matches in Europe - at World Cup host France on Jan. 19 and at Spain on Jan. 22.
U.S. head coach Jill Ellis has named a 26-player roster for those matches, which includes three key players returning from injuries.
Davidson, a rising defensive star, fractured her ankle in September, while Zerboni broke her elbow in September. O’Hara has been out since having ankle surgery in October.
The U.S. will have a one-week training camp in Portugal before heading to France and then Spain.
"It's a real positive to start the year with this training period in Portugal and then play two top teams in France and Spain away," Ellis said in a federation release.
"Finding ways to be successful against European teams in Europe is something every team in the World Cup will have to do to advance deep into the tournament, so this is an essential trip in our prep for the summer."
Following the two friendlies, the U.S. will take on Japan, England and Brazil in the SheBelieves Cup in late February and early March as they continue preparing for the 2019 World Cup.
USWNT roster (caps/goals)
GOALKEEPERS (4): Jane Campbell (Houston Dash; 3/0), Adrianna Franch (Portland Thorns FC; 0/0), Ashlyn Harris (Orlando Pride; 19/0), Alyssa Naeher (Chicago Red Stars; 38/0)
DEFENDERS (8): Abby Dahlkemper (NC Courage; 30/0), Tierna Davidson (Stanford; 12/1), Crystal Dunn (NC Courage; 75/24), Emily Fox (UNC; 2/0), Kelley O'Hara (Utah Royals FC; 112/2), Becky Sauerbrunn (Utah Royals FC; 149/0), Casey Short (Chicago Red Stars; 27/0), Emily Sonnett (Portland Thorns FC; 26/0)
MIDFIELDERS (7): Morgan Brian (Chicago Red Stars; 81/6), Danielle Colaprico (Chicago Red Stars; 2/0), Julie Ertz (Chicago Red Stars; 73/18), Lindsey Horan (Portland Thorns FC; 62/7), Rose Lavelle (Washington Spirit; 20/6), Samantha Mewis (NC Courage; 41/8), McCall Zerboni (NC Courage; 7/0)
FORWARDS (7): Tobin Heath (Portland Thorns FC; 142/25), Carli Lloyd (Sky Blue FC; 265/105), Jessica McDonald (NC Courage; 3/1), Alex Morgan (Orlando Pride;153/98), Christen Press (Utah Royals FC; 106/46), Mallory Pugh (Washington Spirit; 43/12), Megan Rapinoe (Seattle Reign FC; 145/41)