John Still has urged his Dagenham side to tighten up at the back after they lost 3-2 at home to Plymouth.
Strikes from Scott Doe and Jon Nurse hauled Daggers back into the contest, after Plymouth had taken a two-goal lead through Matt Lecointe and Conor Hourihane, before Simon Walton smashed in a last-minute penalty to win it for Argyle.
And afterwards Still insisted his team must improve defensively if they are to make an impression on League Two this year.
"It was a weird game, in the second half we looked more like Dagenham," he said.
"We moved the ball well and got in good areas and I thought we were going to win it. I thought it was one-way traffic, but you aren't going to win games by giving goals away of that ilk.
"We know that our central defenders are two very good players, but they've made mistakes. It's nothing to do with going forward, we won't score bundles, but its conceding goals that are the problem."