By ESPNSTAR.com staff
Campos, who earned 130 caps for Mexico throughout his 18-year career, represented his country at three FIFA World Cups in 1994, 1998 and 2002.
Likewise, Casillas has also played at the biggest event in world football thrice in his career, and captained Spain to their first World Cup victory at the 2010 edition in South Africa.
The 31-year-old has also won five La Liga titles and the UEFA Champions League twice with Real, and Campos has no doubt the Spaniard is currently the best shot-stopper in the planet.
"Casillas is the best goalkeeper in the world," the 45-year-old said on Real's official website. "His reflexes and reactions make him unique.
"He's a leader both on and off the pitch and always appears at the most important moment in the match.
"He's a modest guy and an excellent person, in spite of everything he has won. He's a very special guy who has earned worldwide recognition.
"He has a lot to teach young goalkeepers."
Casillas has earned 137 caps for Spain since making his international debut in 2000 and has also played 625 games for Los Blancos.