After a disappointing draw at Bolton and a smash-and-grab victory at Valencia, the Reds were on the back foot for long periods at the Stadium of Light, as Steve Bruce's side sought to exploit United's exertions of the last six days.
"That's the way we expected Sunderland to play, because they knew we had games on Sunday and Wednesday," Van der Sar told MUTV. "It was a lot of travelling, plus coming up here on Friday was also four hours all in all, so that's exactly the way we expected them to play against us.
"We were happy to go in at half-time with a nil-nil. In the last 15 minutes we had one or two chances, but not enough to get the winner. I don't think we put enough in our offensive game to really claim the three points. I don't think the service was sufficient to get the goal in the end.
"We can be happy that we had a clean sheet, the second in a row after Valencia on Wednesday, but I think it was two dropped points today, because we dropped too many already in away games.
"We were disappointed with a draw at Bolton, we got a nice win in Valencia which sets us well for the Champions League and of course today you're looking for a win to close the gap a little bit. Now you have to hope that Chelsea and Arsenal draw tomorrow."