John McMahon blamed "needless mistakes" for Tranmere Rovers' 2-0 away defeat at Crawley Town.
Goals from Matt Tubbs and Gwion Edwards gave the hosts the win as Tranmere stayed three points above the bottom four.
McMahon said: "The first half was a lacklustre display and we were always up against it.
"Too many players were poor in the first half. The performance levels need to improve if we are to get anything from games.
"We knew they'd be direct and they're a difficult side to play against but we have created our own problems by giving the ball away too easily. There were needless mistakes that we need to improve on.
"It was poor from our part giving the free kick away [for the first goal].
"The lads know they need to be disciplined and patient, but it was a bit of eagerness from Max to want to nick the ball away. It was a good finish to be fair.
"Overall, we've probably had the better opportunities. In the second half we were a lot better and more threatening. We looked as though we could score but we left ourselves vulnerable late in the game."
The caretaker manager continued: "I can knock the lads for quality but for effort and endeavour, I can't knock them.
"It's another tough game [on Friday at Gillingham].
"We'll pick our heads up and go again. The lads know what's expected of them - and that's competing more and winning football matches.
"We know we need wins and we know we need to stay out of the bottom four."
Meanwhile, the club offered "a big thank you" to all the Tranmere fans who have already signed up for 2014-15 by purchasing a season ticket.
Support in the first six days of reduced price season ticket offers means sales are up a massive 58% on last season's figures at the same stage.