Team USA soccer faces Portugal on Sunday, 6pm (listen 97.3 ESPN) and a draw there could be enough to push them through to the knockout round.

United States forward Jozy Altidore will miss Sunday's Group G World Cup match vs. Portugal due to strained left hamstring, the U.S. federation confirmed on Thursday.

"He will not be available for Sunday's game, but we are hopeful he will be available in the tournament," U.S. Soccer spokesman Michael Kammarman said of the 24-year-old.

The Americans complete the first round against three-time champion Germany on June 26. Aron Johannsson replaced Altidore for the second half against Ghana. Chris Wondolowski is the other striker in the squad who could join Clint Dempsey in the attack.

Altidore left the Americans' World Cup opener against Ghana after straining his left hamstring in the 21st minute of Monday's 2-1 win against Ghana, leaving his status for the remainder of the World Cup in question.

The 24-year-old forward was running down a ball with Ghana's John Boye when he lowered his head to attempt to control it, grabbed the back of his left leg and fell to the ground. Wincing in pain, Altidore was taken off on a stretcher.

Kammarman also said that Matt Besler should be available for Sunday's game in Manaus, and that Dempsey hasn't made a decision on wearing a mask. Dempsey scored 30 seconds into Monday's 2-1 win over Ghana, then was bloodied by a shin to the face from Boye when they battled for a header in the 33rd minute.

He added that the U.S. team travels with masks, so Dempsey wouldn't necessarily have to have one custom-made.

Besler exited the match against Ghana at halftime as a precaution after tweaking his hamstring.

(Copyright 2014 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.)