Philipp Kohlschreiber of Germany returns a ball to Tomas Berdych of Czech Republic during the Davis Cup World Group first round tie between Germany and Czech Republic at the TUI Arena in Hanover, Germany, 06 March 2016. EPA/JULIAN STRATENSCHULTE

German Davis Cup team players (L-R) Philipp Petzschner, Dustin Brown, Alexander Zverev, and Philipp Kohlschreiber line up before the Davis Cup World Group 1st Round tie between Germany and the Czech Republic in Hanover, Germany, 04 March 2016. EPA/JULIAN STRATENSCHULTE

Mike Bryan (back) and Bob Bryan (front) of the USA in action against Australian players Lleyton Hewitt and John Peers during their doubles match of the Davis Cup World Group first round tie between Australia and the USA at the Kooyong Lawn Tennis Club in Melbourne, Australia, 05 March 2016. EPA/TRACEY NEARMY

Novak Djokovic of Serbia returns to Mikhail Kukushkin of Kazakhstan during the Davis Cup World Group first round tie between Serbia and Kazakhstan at the Aleksandar Nikolic Arena in Belgrade, Serbia, 06 March 2016. EPA/KOCA SULEJMANOVIC

Chilean players Julio Peralta (R) and Hans Podlipnik (L) in action against Jose Hernandez (2R and Manuel Castellanos (2L) of the Dominican Republic in the first round of American Zone of David Cup in Santiago de Chile, Chile, 05 March 2016. EPA/MARIO RUIZ