John Isner has withdrawn from the Hopman Cup because of a right knee injury, ending the American team's chances of reaching the tournament final.
Spain and the U.S. were each 2-0 in round-robin play heading into Thursday's deciding match-up. Spain was awarded a walkover into the final.
Isner's knee was strapped during his loss to Jo-Wilfried Tsonga of France on Tuesday and he later said he was suffering from ''a little tendinitis.''
Although Spain was assured of advancing to the final, Venus Williams was still scheduled to play Spain's Anabel Medina Garrigues in women's singles and will partner with Isner's Australian hitting partner, Thanasi Kokkinakis, to play Fernando Verdasco and Medina Garrigues in mixed doubles.