Through the opening six rounds unforced errors were undermining the Warriors' performances before second-half lapses in consecutive weeks allowed both the Cowboys and Titans to conjure come-from-behind victories.
Those late fades were partly attributed to exhaustion from the extra defensive work the Warriors had to do on the back of the unforced errors that have plagued the team.
McFadden believes eradicating basic mistakes will lead to improvements elsewhere.
"A bit of that in the second-half is about what we are doing to ourselves in terms of energy and the errors we make," he said. "They're fundamental errors that are confined to a small group of individuals and they've got to take responsibility for that. If we can eliminate those out of our game it's a different story."
Captain Simon Mannering agreed a heavy defensive workload over the first two months of the NRL had taken its toll and affected the side's ability to hang tough when defending their line.
"It's probably come off the back of doing a lot more defending than what we should do," Mannering said.
"Obviously that's on the back of errors and we're not using the ball as well as what we could have and turning over a lot of possession.
"It's a flow-on effect from that and if we can get that right, where we're not forcing ourselves to do more work when we don't have to, hopefully our defence gets better and we can put ourselves in a position to get the result."
Fullback Sam Tomkins' return from a knee injury has been delayed.
The England international now eyes a return in the round 12 home game against the Newcastle Knights.
"We were hopeful we'd get him back within the more aggressive timeline of six weeks but he's probably going to be another couple of weeks on the sidelines," McFadden said. "He's unlikely for the Parramatta game next week so hopefully we'll get him back after the bye."
