Iker Casillas is well respected in the football world. Here he is with former Real teammates Michel Slagado and Luis Figo, right. Felipe Trueba / EPA
Iker Casillas, right, celebrates with teammate Santi Cazorla during Spain's 2008 European Championship title run. Shaun Botterill / Getty Images
Spain captain, Iker Casillas lifted the 2010 World Cup in South Africa. Michael Kooren / Reuters
Iker Casillas led Spain to a successful European Championship defence in Kiev, Ukraine, in 2012. Jasper Juinen / Getty Images
Iker Casillas, right, was instrumental in Real Madrid's Uefa Champions League victory in 2014. Victor Carretero / Getty Images
Former Real Madrid captain and goalkeeper Iker Casillas won 16 trophies at the Bernabeu before leaving for Porto 2015. Andrea Comas / Reuters
Jurgen Klopp, left, greeted Iker Casillas after Liverpool beat Porto in their Uefa Champions League quarter-final last month. Armando Franca / AP Photo
Iker Casillas is well respected in the football world. Here he is with former Real teammates Michel Slagado and Luis Figo, right. Felipe Trueba / EPA
Iker Casillas, right, celebrates with teammate Santi Cazorla during Spain's 2008 European Championship title run. Shaun Botterill / Getty Images
Spain captain, Iker Casillas lifted the 2010 World Cup in South Africa. Michael Kooren / Reuters
Iker Casillas led Spain to a successful European Championship defence in Kiev, Ukraine, in 2012. Jasper Juinen / Getty Images
Iker Casillas, right, was instrumental in Real Madrid's Uefa Champions League victory in 2014. Victor Carretero / Getty Images
Former Real Madrid captain and goalkeeper Iker Casillas won 16 trophies at the Bernabeu before leaving for Porto 2015. Andrea Comas / Reuters
Jurgen Klopp, left, greeted Iker Casillas after Liverpool beat Porto in their Uefa Champions League quarter-final last month. Armando Franca / AP Photo
Iker Casillas is well respected in the football world. Here he is with former Real teammates Michel Slagado and Luis Figo, right. Felipe Trueba / EPA