Altidore injured his hamstring in the win over Ghana on June 16 in the team's first group stage match, but head coach Jurgen Klinsmann was optimistic that his best offensive threat would contribute in some way on Tuesday.
"We don't know how much, but he's available," Klinsmann said. "This is what we wanted. This is what we hoped for. This is what the medical staff has been working for since the injury. "They worked day and night with Jozy, and just having him is huge. How many minutes? We'll see that during the game."
Klinsmann did not say how much Altidore has trained at full speed, but indicated the medical staff worked hard with Altidore over the weekend in anticipation of a return to action.
"It's difficult to say with Jozy in the two or three days he's been with the team, how much work is in his legs," Klinsmann said. "There's a lot of individual stuff going on, but it's not clear to say how many minutes [he can play]."
Whether he starts or not is still in question, but just having Altidore back in the fold will be a major boost as the Americans look to advance to the quarterfinals for the first time since 2002.