Jozy Altidore suffered a hamstring injury Monday vs. Ghana. (By Dolores Ochoa — Associated Press)

SAO PAULO — Jozy Altidore has been ruled out of the U.S. national team’s World Cup match against Portugal on Sunday because of a strained left hamstring, a long-anticipated announcement made by the U.S. Soccer Federation on Thursday.

Altidore will continue undergoing treatment in hopes of returning to match fitness at some point in the tournament, USSF spokesman Michael Kammarman said. However, with two Group G games over the next week, the striker is not expected to play again unless the Americans advance to the knockout stage.

Even then, his availability is uncertain. The USSF declined to discuss the severity of the injury, suffered in the first half of the 2-1 victory over Ghana on Monday in Natal. Altidore underwent an MRI scan upon the delegation’s return to Sao Paulo on Tuesday.

Meantime, central defender Matt Besler, who departed at halftime of the Ghana match with tightness in his right hamstring, trained with the team Thursday and will be available for selection against Portugal.

Despite suffering a broken nose Monday, captain Clint Dempsey is planning to start again this weekend in Manaus. He has not decided whether to wear a protective mask.

With Altidore out, Coach Jurgen Klinsmann will weigh replacing him with another forward or use five midfielders behind Dempsey.

“It’s bad news, but the team will handle it,” midfielder Jermaine Jones said of Altidore’s injury. “I don’t know how [Klinsmann] will play and what formation he will play. But everybody is ready and wants to make the next step.”


Follow Thursday’s game on the World Cup live blog

Previewing Thursday’s World Cup games

John Brooks of U.S. rises from obscurity with winning goal vs. Ghana

Ghosts of 1950 loss to Uruguay still haunt many in Brazil

Defending champion Spain is eliminated with loss to Chile

Netherlands escapes Australia, clinches advancement

Croatia stays in running with rout of Cameroon

Revisit all of Wednesday’s action on the World Cup live blog

#Persieing: The Dutch star’s 93-year-old grandfather joins the trend

U.S. team awaits word on Altidore injury

Isolated Amazon city of Manaus celebrates its World Cup spotlight

Analyzing the goal scoring at the World Cup

Scores and schedule | Group standings | Stats leaders