Pardew has admitted that his side are beginning to feel frustrated with their inability to find form in the closing stages of the season.
"It was a tough afternoon for us and we weren't at our best," the Newcastle boss told BBC Sport.
"We are lacking a bit of quality at the moment and we are trying to get that on the pitch. We had some good effort and commitment today, certainly better than Southampton, but I'm afraid it wasn't good enough against a decent Manchester United.
"We have got loads of players missing and it is really hurting us at the minute. We are desperate to get another three points, a win and a goal for them (the fans) but it is just not happening for us at the moment."
The Magpies are currently ninth in the Premier League.