Evans scored his second goal of the season against Braga on Tuesday night as United fought back from two goals down.
It keeps their brilliant run in the competition this season going at 100% win rate, but boss Alex Ferguson is baffled by the defence.
United have fallen behind in eight of their twelve games this season and Evans believes that it is just not good enough for a team like United.
He told ESPN: "We lost the two goals early doors so we were glad to get the result in the end. It's happened quite a lot and is becoming a bit of a habit.
"Hopefully it's something we can eradicate, as we don't want to give ourselves that kind of deficit at the start of games. We need to get a better start in future, especially at Chelsea on Sunday."