Davis Cup

Croatia's Marin Cilic celebrates after winning a point against Argentina's Federico Delbonis, during their singles match at the Davis Cup tennis tournament final between the two countries in Zagreb, Croatia, Friday, Nov. 25, 2016. (AP Photo/Darko Vojinovic)

Darko Vojinovic/AP

Croatia’s Marin Cilic celebrates after winning a point against Argentina’s Federico Delbonis, during their singles match at the Davis Cup tennis tournament final between the two countries in Zagreb, Croatia. Photo Darko Vojinovic/AP 

Fans of Great Britain show their support during day one of the Davis Cup Final at the Flanders Expo Centre, Ghent. PRESS ASSOCIATION Photo. Picture date: Friday November 27, 2015.

Andrew Milligan/PA

Fans of Great Britain show their support during day one of the Davis Cup Final at the Flanders Expo Centre, Ghent

A supporter of the Czech Republic cheers during the quarterfinal of Davis Cup World Group tennis at Ariake Colosseum in Tokyo.

Shizuo Kambayashi/AP

A Czech Republic supporter cheers during the quarter-final of Davis Cup World Group tennis at Ariake Colosseum in Tokyo.