HARRISON, N.J. — The United States’ fate at the Women’s World Cup may hinge on Alex Morgan’s left knee.

The 25-year-old star forward missed her third straight game because of a bone bruise, a listless 0-0 draw against South Korea on Saturday in their final warm-up match.

Morgan hasn’t played in a month but says she will be ready for the Americans’ opener against Australia on June 8. Coach Jill Ellis, trying to lead the U.S. to its first World Cup title in 16 years, said Morgan will have to build her minutes at the tournament in Canada.

“We need her. We need her to win,” said forward Abby Wambach, who may get more playing time because of Morgan’s injury. “I’m comfortable if she doesn’t start games. I’m comfortable if she comes off the bench, that we still are successful throughout this World Cup.”

Three days shy of her 35th birthday, Wambach started in her 242nd international appearance in the only change by Ellis from the starters in the 5-1 win over Mexico on May 17. Wambach replaced Megan Rapinoe, who had a sore quadriceps in training Friday.

While the U.S. outshot the South Koreans 15-7, the Americans had few good scoring chances. The best was in the 36th minute, when Wambach was 1 yard from an open goal line and couldn’t get her head on Meghan Klingenberg’s cross from the left flank. South Korea goalkeeper Kim Jungmi stuck out her right hand to bat away Carli Lloyd’s open 10-yard shot in the 49th minute after Morgan Brian pulled the ball back.

“Now’s the time to get everything out of our system before we head over there,” Lloyd said. “We’ll be just fine.”

The U.S. leaves by charter jet Tuesday for its training base in Winnipeg, Manitoba.