David Villa and Sergio Garcia have pulled out of Spain's final Euro 2008 warm-up game due to injury.
Garcia has a calf problem while fellow striker Villa is suffering from a right thigh injury after a training ground incident on Tuesday.
Tests have revealed a major bruise and team doctor Jorge Candel has voiced his concerns over the Valencia forward's condition.
"The Villa injury is worrying us the most," Candel told reporters.
"He's got an injury in a muscle that shouldn't cause too much of a problem but we will have to see how it evolves over the next few days."
Both players will miss Wednesday's clash with USA, while Fernando Torres was already a doubt for the match with a slightly twisted ankle.
Iniesta on the mend
Midfielder Andres Iniesta is another player who will sit out the match after being treated for a severe bout of food poisoning.
Iniesta visited hospital earlier this week but he is now recovering well and should be able to resume light training on Thursday.
He is expected to be available for Spain's opening Euro 2008 game against Russia next Tuesday.
Luis Aragones' side face Sweden on 14th June and then defending European champions Greece in their final Group D game four days later.