Altidore out of Portugal clash, but Dempsey fit
The Sunderland frontman was forced from the field after hurting his hamstring in a 2-1 win over Ghana on Monday, plunging his future involvement in Brazil into serious doubt.
US Soccer have now confirmed that the player will be absent for their second Group G encounter, but offered no hint as to his long-term fitness.
There was better news for two of Jurgen Klinsmann's other injury concerns.
Matt Besler, who also suffered a hamstring problem in the Ghana fixture, is fit and available for selection, while Clint Dempsey is expected to start despite suffering a broken nose in the same game.
The captain opened the scoring in the US curtain-raiser, tucking the ball home in the opening minute, before Jack Brooks headed home a late winner.