Burton Albion manager Nigel Clough was critical of his side's poor defending during their shock 4-2 defeat to Northampton in the third-round of the FA Cup on Sunday.
The League One Brewers were strong favourites for the tie given they had home advantage and were 20 places above their visitors on the football ladder ahead of kick-off.
But they were second-best throughout and couldn't recover from a shocking first-half, trailing 3-0 after 45 minutes following goals from Nicky Adams, Ryan Watson and Charlie Goode.
Ryan Edwards pulled one back and Scott Fraser netted late in the second-half but Sam Hoskins struck in-between those goals to dump Burton out of the competition.
Clough told the club website: "It's pure disappointment being knocked out of the FA Cup and conceding four goals - that's 11 in the last four games and we haven't kept a clean sheet for a long time.
"To go 3-0 down inside 45 minutes was extremely poor from our point of view. They scored from two set plays and a cross and we are doing nowhere near enough to keep the ball out of our net.
"The whole team has to do more to protect the goal and keep the ball out. Although we are still attacking well and creating chances you are asking an awful lot to score four goals at home just to get a replay.
"We are getting punished. Every time the ball goes into our penalty area it seems to go in the back of the net. But it's little things that are costing us goals when people aren't quite doing their job well enough.
"We had our situations again throughout the game and I felt in that period just after half-time if we had got one back we could have had a comeback on our hands but, for 20 minutes, we couldn't put the ball in the net.
"It's not just losing the game today and getting knocked out. It's a big financial blow to the club. That limits us straight away with what we can do in the transfer widow."