The Galatasaray star was unable to make his mark against his former team as he was replaced at half-time when his side were 2-0 down
The Netherlands international featured from the start at the Santiago Bernabeu, but was taken off at half-time after failing to make an impact in the opening 45 minutes.
"Of course I am disappointed. I wanted to finish this game, especially here at the Santiago Bernabeu where I played in the past. I was unable to do that and that's disappointing," the Dutchman told NOS.
"I am in good physical condition and I'm feeling good. I did have a few minor physical problems, though, because I had to do a lot of running. But that's not an excuse, because it's clear that I should have offered more.
"Normally, I receive the ball between the lines when I am available for one or two seconds, but not this time. When that doesn't happen, you're pretty much invisible. It might have looked pretty bad, but it wasn't that poor."
Galatasaray will be looking to bounce back from their loss to Madrid on Saturday when they host Mersin Idman Yurdu.