Two-time Masters champion Bubba Watson has withdrawn from the American team for the World Cup of Golf in Melbourne, citing scheduling and personal reasons.
The world No.6 has been replaced by No.8 Rickie Fowler, who has selected No.19 Jimmy Walker as his partner in the two-man US team for the event at Kingston Heath from November 23-27.
Fowler and Walker will both be playing in the World Cup for the first time.
"Coming off the amazing experience that I had at the Olympics, it's great to have the chance to put on the red, white and blue again and play for the United States in the World Cup of Golf," Fowler said on Wednesday.
"Jimmy is not only one of my favorite guys out here on tour but he is clearly one of the most talented players on our tour as well.
"I think we'll make a fantastic team and our strengths will work well together."
Argentina's Emiliano Grillo has also withdrawn.
New Zealand's Danny Lee confirmed his selection of Olympic teammate Ryan Fox as his partner for the 58th edition of the event.