With Brisbane losing to Melbourne on Friday and Parramatta going down to Canberra on Saturday, the Warriors' destiny was in their own hands against Penrith on Sunday night.
The Panthers needed to win to book a top-four spot, but a two-point defeat for the Warriors would have been enough to finish above the Broncos on points differential.
But it proved to be too big a hurdle as the impressive Panthers won 22-6 at Sportingbet Stadium leaving the Warriors to ponder another year where they combined brilliance and mediocrity all too regularly.
A slow start to the year saw coach Matt Elliott shown the door, and although things did improve under McFadden the team was found wanting at the back end of the season.
"We didn't really fire a shot," McFadden said.
"We had opportunities, we didn't take them and weren't good enough.
"We just weren't tough enough to get ourselves out of it.
"It's really disappointing. We know we've made some real progress this year and it would have been nice to get that result and get in the eight.
"It's a dose of reality of where we sit."
Skipper Simon Mannering said there were no excuses for another year of failure and the time had come for the whole team to take responsibility for another disappointing campaign.
"It wasn't an ideal start to the year but we should have given ourselves opportunities throughout the year to be there in the eight," Mannering said.
"I guess it showed tonight we didn't quite deserve it and we're not good enough.
"It's something we have to learn from for next year. We didn't have that spark which is a shame because we had everything to play for."
