Sauerbrunn, who won two World Cups with the USWNT, confirmed in a statement she will not recover in time from her injury and will miss the tournament, which kicks off on July 20 in Australia and New Zealand.
"Heartbroken isn't even the half of it. But that's sports for you and that's life," Sauerbrunn said. "I had hoped and worked and hoped some more to make it back in time to help lead the team at this World Cup, but after lots of discussion, unfortunately, there's just too much variability in my return to play timeline.
Sources told ESPN that Sauerbrunn suffered a setback of her foot on June 3 when she played for the Portland Thorns FC her first match since the injury.
"I'll be home, working as hard I can to get back on the field as quickly as I can. It's been an honor to work and play alongside this incredible group of athletes. They have my unwavering support. And, more importantly, they have my unyielding belief," the 38-year-old defender added.
"This program has always been about the collective and I have no doubt that the twenty-three players on the final roster have everything they need-in their feet, their heads and their hearts-to bring our fifth trophy home. To my teammates, I love you."
Sauerbrunn is one of several injured American players to miss the tournament, after attacker Mallory Swanson went down with a knee injury in April.
Sauerbrunn, 38, is one of the team's longest-standing players with 216 international appearances. She helped the Americans to World Cup titles in 2015 and 2019. Her most recent international appearance was a friendly against Ireland in April.
Head coach Vlatko Andonovski is set to announce his 23-player squad imminently and reports said he informed players Thursday of whether he planned to include them.
Information from Reuters was used in this report.