Hernandez came off the bench on Wednesday adn scored his first goal for United in their 5-2 triumph.
“We scored some top quality goals and we’re all delighted that Hernandez got himself on the scoresheet in his first game,” said Van der Sar.
“He looks very sharp and has a good eye for goal. You could see his quality from the first chance he had just before he scored. The finish for his goal was tremendous.”