"We wanted to play in the Champions League because we know how good it can be. We've been in a final and a semi-final over recent years and we want more," said the Dutch international.
"First we have to win the qualifier and this was a tough game. We believed in ourselves and even though it wasn't our best performance, we always know we have the quality to score.
"Standard Liege were really tough opposition, they were really fighting for the 90 minutes in both matches and in extra time and maybe they deserved more, but that's football. We are just relieved to be through."