Nathan Chen, who at 16 became the youngest man to finish in the top three at a U.S. Figure Skating Championships since 1973 on Sunday, will miss the World Championships due to left hip surgery after suffering an injury in a jump attempt in an exhibition later Sunday.
Chen is out eight to 10 weeks after aggravating a pre-existing injury and will be replaced on the Worlds team by Grant Hochstein, who finished fourth at the U.S. Championships.
Hochstein will make his Worlds debut, joining U.S. champion Adam Rippon (fourth Worlds appearance) and silver medalist Max Aaron (third Worlds).
Worlds are in Boston in two months.
Chen landed a record six quadruple jumps over two programs at Nationals in St. Paul. He will also miss the World Junior Championships due to the hip surgery.