The goalkeeping legend has praised the Real Madrid skipper for his enduring quality since making his debut for the club as a teenager
The Spain star has been sidelined since fracturing his thumb during the Copa del Rey clash with Valencia on January 20, but has been named in Real Madrid's travelling party for the second leg of their last 16 Champions League clash at Old Trafford.
Prior to his injury, Casillas had lost his place in the Blancos line-up amid rumours of a bust-up with coach Jose Mourinho.
But Van der Sar has moved to heap praise on the 31-year-old and hail his impact for both club and country since making his debut back in 1999.
"What can we say about Casillas? He is 31-years-old and has won everything," he told reporters.
"I think he started playing for the first team of Real Madrid at the age of 17 or 18 , that says everything.
"He has been wonderful for all this time for both Real Madrid and the Spanish national team.
"I do not know him personally, but I see him, I read his interviews, and I've never heard anything bad about him. He's a great captain for Real Madrid and for Spain."
Los Blancos face Sir Alex Ferguson's men on Tuesday, with the game tied at 1-1 after the first leg at the Santiago Bernabeu.