The reigning Premier League champions slumped to a 2-1 loss to Tottenham at Old Trafford on New Year's Day - their fourth reverse at home under new manager David Moyes.
"It is hard to explain," said Northern Ireland defender Evans. "They caught us on the break a little bit for the two goals so maybe we need to be a bit more patient.
"Away from home, you tend to be more defensive in your set-up. Maybe at home we are leaving ourselves a bit too open.
"We want to entertain our fans and score goals but maybe that is to our detriment a little bit."
"It is disappointing but we will keep plugging away. We actually played quite well in the previous six games but we have started the New Year on a bad foot and we need to get positive results again."
The Red Devils now find themselves languishing in seventh place in the Premier League - some 11 points shy of leaders Arsenal.