PORTLAND, Ore. – U.S. women's national team forward Alex Morgan had surgery on her right knee and is expected to be out for three to four weeks.

Morgan, who plays for the NWSL's Portland Thorns, underwent the procedure to remove a plica, or a small fold in the lining of the knee joint that was causing irritation.

Morgan was on the U.S. team that won the World Cup earlier this month in Canada. The Americans beat Japan 5-2 in the final.

Morgan did not play in matches leading up to the monthlong World Cup because of a bone bruise in her left knee. She came in as a substitute in the first two games of the tournament as she returned to form.

U.S. Soccer said Morgan could return for the first of a 10-match victory tour on Aug. 16 against Costa Rica in Pittsburgh.