Captain Luke Shiels says Boston United need to cut out the silly goals.
The centre back returned from injury as the Pilgrims were beaten 4-1 at Southport On Saturday, a week after their miserable 4-0 thumping at Chester.
Fraser Preston's finish had given United hope after Marcus Carver and Jordan Archer put the Port 2-0 up, only for Carver to complete his hat-trick late on.
"Speechless, just how we give away silly goals," Shiels said.
"We can't seem to defend at the minute, everything that ends up in the box ends up in the net.
"As defenders we're letting the side down massively, the strikers we're not really giving them a chance.
"Fraser's got a goal, we look like we can get back in the game and then all of a sudden we go and concede goals.
"It's eight goals in two games and it's not good enough."
United have won seven and lost six games so far this campaign, with five of those defeats coming on the road.
Shiels has been part of a traditionally stoic Boston backline in recent campaigns, and he wants a return to that miserly form.
"They are soft goals, there's not many goals you say I take my hat off to them. They're silly goals," he told BBC Radio Lincolnshire.
"I can't put my finger on why we're conceding these silly goals.
"My third season here and my first two seasons, our defensive record was fantastic - one of the best in the league two seasons running.
"We just can't seem to defend. It's not always the back four, yeah today the back four's let the side down. But as a team we need to be better.
"It starts from the front, we defend from the front but today it's balls into the box and we need to be holding our hands up, especially myself.
"As captain of the club it's not good enough."
Although United remain in the play-off spots, manager Craig Elliott has come under pressure from some sections of the suport following the recent form.
But Shiels has defended his boss.
He added: "Every single game's massively important at the minute, but these two games (Chorley and Darlington at home) - it's left to us.
"The gaffer can only do so much and what he's doing is fantastic. It's only the players, it's not the gaffer and the backroom staff - it's us.
"Once we cross the line it's left to us, the 11 out there."