Croatia's Ivica Kostelic skis during the first run of the men's slalom at the Sochi 2014 Winter Olympics, Saturday, Feb. 22, 2014, in Krasnaya Polyana, Russia. (AP Photo/Alessandro Trovati)
Kei Nishikori, of Japan, reacts after his return to Ivo Karlovic, of Croatia, in the singles final at the U.S. National Indoor Tennis Championships, Sunday, Feb. 16, 2014, in Memphis, Tenn. (AP Photo/Rogelio V. Solis)
Ivo Karlovic, of Croatia, hits a return to Kei Nishikori, of Japan, in the singles final at the U.S. National Indoor Tennis Championships on Sunday, Feb. 16, 2014, in Memphis, Tenn. (AP Photo/Rogelio V. Solis)
Kei Nishikori, of Japan, hits a return to Ivo Karlovic, of Croatia, in the singles final at the U.S. National Indoor Tennis Championships on Sunday, Feb. 16, 2014, in Memphis, Tenn. (AP Photo/Rogelio V. Solis)
Ivo Karlovic, right, of Croatia, congratulates Kei Nishikori, of Japan, for winning the singles final 6-4, 7-6 (0) at the U.S. National Indoor Tennis Championships, Sunday, Feb. 16, 2014, in Memphis, Tenn. (AP Photo/Rogelio V. Solis)
Ivo Karlovic, of Croatia, hits a backhand return to Kei Nishikori, of Japan, in the singles final at the U.S. National Indoor Tennis Championships on Sunday, Feb. 16, 2014, in Memphis, Tenn. (AP Photo/Rogelio V. Solis)
Ivo Karlovic, of Croatia, serves to Kei Nishikori, of Japan, in the singles final at the U.S. National Indoor Tennis Championships on Sunday, Feb. 16, 2014, in Memphis, Tenn. (AP Photo/Rogelio V. Solis)
Kei Nishikori, of Japan, hits a return to Ivo Karlovic, of Croatia, in the singles final at the U.S. National Indoor Tennis Championships on Sunday, Feb. 16, 2014, in Memphis, Tenn. (AP Photo/Rogelio V. Solis)