Tiafoe replaces Del Potro at Laver Cup in Chicago

              Frances Tiafoe of the United States returns a shot to Croatia's Borna Coric during their Davis Cup semifinal singles match between Croatia and the United States in Zadar, Croatia, Sunday, Sept. 16, 2018. (AP Photo/Darko Bandic)

CHICAGO (AP) — U.S. Open runner-up Juan Martin del Potro has withdrawn from Team World at the Laver Cup this weekend and has been replaced by American Frances Tiafoe.

Del Potro, of Argentina, lost to Novak Djokovic in straight sets in the U.S. Open final.

Djokovic will play for Team Europe at the Laver Cup, which begins Friday at United Center. Each team has six players, including Roger Federer (Team Europe) and Kevin Anderson (Team World). The event features best-of-three set singles and doubles. The final is Sunday.

Tiafoe played for Team World at the inaugural Laver Cup in Prague last year. He lost to Croatia’s Borna Coric in a deciding five-set match in the Davis Cup semifinals last weekend.