Boss feels his side lacked fight in the second half.
Southend United manager Phil Brown was bitterly disappointed as his side suffered a late 2-1 defeat to ten-man Burton Albion at the Pirelli Stadium.
Barry Corr had his penalty saved before putting the Blues in front soon after, before Robbie Weir was shown a straight red for Albion for an elbow to the face of Corr.
But the Brewers battled back in the second half, and after Matty Palmer had equalised just before the hour mark, another substitute, Nasser El Khayati won the game for Jimmy Floyd Hasselbaink's side.
“I hold myself responsible for everything that happened,” Brown said after the game.
“I blame myself for that final substitution. I made the change and we ended up losing the game, so it's my fault.
“We applied ourselves in the right manner in the first half. We got a penalty out of nothing, but we didn't take the opportunity. He takes his chance ten minutes later, but there's no excuses for that second half performance.
“I can't legislate why we dropped off in the second half and the standard of the performance. Burton ran out worthy winners, but I'm not here to applaud them. It simply wasn't good enough and not acceptable.
And the boss felt his side never dealt with the Brewers frontman Stuart Beavon, and conceded his side lacked 'fight' in the second half.
“We will have to fight more in the next nine games. We were physical in the first half but weren't in the second. We didn't compete well enough. They went down to ten men and that galvanised them. The second half lacked idea and any kind of positive thought process.
“We had four against one in the second half and that one won the battle. [Stuart] Beavon caused us problems and we never dealt with him.
“The second half performance was negative and wasn't us. Our mentality was wrong, and that was why we lost the game.”