The 32-year-old attacker, bidding to make his fourth World Cup, was bypassed by U.S. coach Jurgen Klinsmann in favor of Aron Johannsson and Chris Wondolowski, who joined Jozy Altidore and Clint Dempsey as the forwards.
Also cut were defenders Brad Evans, Clarence Goodson and Michael Parkhurst, midfielders Joe Corona and Maurice Edu, and forward Terrence Boyd.
Donovan has 57 goals in 156 international appearances and has been the face of American soccer for the past decade, both with the national team and with Major League Soccer, where he has won five titles.
Donovan was a mainstay of the national team before he took a sabbatical of about four months after the 2012 season, spending part of the time in Cambodia. Klinsmann said Donovan would have to earn his spot back.
He restored Donovan to the roster for last summer's CONCACAF Gold Cup, where Donovan excelled, and played Donovan for World Cup qualifiers later in the year. But Klinsmann kept him out of the starting lineup for last month's exhibition against Mexico, saying Donovan practiced poorly because of a knee problem.
Donovan said this week his knee was OK.
"I'm very confident in my abilities and I think I'm deserving to be a part of the squad, but I have to prove that and I have to earn it," he said Monday.
When Klinsmann announced his 30-man preliminary roster on May 12, he said he viewed Donovan more a forward than a midfielder.
"I don't have that youthful energy and excitement that I did in 2002, but I see the game and I see the situation a lot more clearly now, so I'm able to I think enjoy it more in that way," Donovan said. "When you're younger, you're just sort of going crazy to do whatever it takes to make the team and you forget to enjoy it, And now I'm actually getting to enjoy it."