see more

MADRID, SPAIN - MAY 11: Rafael Nadal of Spain and Kei Nishikori of Japan hold their trophies after Nishikori retired injured in the third set in their final match during day nine of the Mutua Madrid Open tennis tournament at the Caja Magica on May 11, 2014 in Madrid, Spain. (Photo by Clive Brunskill/Getty Images)

MADRID, SPAIN - MAY 11:  Rafael Nadal of Spain and  Kei Nishikori of Japan hold their trophies after Nishikori retired injured in the third set in their final match during day nine of the Mutua Madrid Open tennis tournament at the Caja Magica on May 11, 2014 in Madrid, Spain.  (Photo by Clive Brunskill/Getty Images)