Jim Bentley said he felt his side “were beating themselves” after slipping to a third straight defeat on Saturday.
A Scott Boden double was enough for Newport County to win 2-1 despite Shaun Miller’s fine leveller on the hour mark.
The Shrimps had hoped to bounce back from the defeat by the same scoreline to Mansfield on Tuesday night but defensive frailties cost them once again.
Bentley said: “I think we’ve beaten ourselves in the last two games.
“On Tuesday it was ridiculous how we lost that game after being 1-0 up.
“We had a good chat but started poorly today, the corner’s come in, we’ve lost the flight of the ball and the lad’s tapped it in.
“It can happen but it’s not happening for us at the minute.
“We responded well and created chances. The conditions were terrible but when we had the wind we got back into it with a great strike from Shaun Miller.
“Then it looks like we’re just going to step on and go but they have one break down the right, a cross into the box and tuck it away.
“We had chances to get back level but didn’t take them. We’ve got to tighten up at the back and we’ve got to tighten up going forwards because we are creating chances.
“We were the second leading goal scorers in the division before today but at the back has been our Achilles heel this season.
“We’ve just got to remain positive and come out fighting again on Tuesday."