The Red Devils fell to consecutive home Premier League defeats for the first time since 2002 on Saturday, courtesy of their 1-0 loss to Newcastle United.
David Moyes's side have failed to score in their last two matches at Old Trafford and Evans has confessed that their offensive play is suffering from the low morale brought about by below-par results.
"Obviously the lads have lost a bit of confidence in their play," Evans told reporters. "Players maybe are not playing how they naturally would. That happens when your confidence drops.
"You can tell that with the possession and creativity. Usually whenever we're chasing a goal at Old Trafford, especially at the Stretford End, we put teams under an enormous amount of pressure.
"If you look back at the game, we lacked a bit of sharpness in our passing. When we were going forward, the lack of sharpness in our passing stopped us from creating much up front."
United will be 15 points behind table-topping Arsenal if the Gunners beat Everton this afternoon.