Vidic says the players are understandably disappointed with the outcome and must be more clinical in front of goal in their next outing at home to Fulham on Saturday.
"We knew it would be a hard game," he told MUTV afterwards. "They did what they're best at - playing long balls and focusing on set-pieces. They had a few chances and in the end deserved to score, but we're never happy when we concede from a set-piece.
"We had some possession but we weren't clinical. When you go away from home you expect the home side to have some chances, but we need to be more clinical.
"It wasn't a great game but we're already looking forward to the next one. We've lost our first match [of the season] in the past and finished well so hopefully we can win our next game and go on a long run."