Deeping must have wandered how they went home empty-handed on Tuesday night.
The Lincolnshire side should have been well out of sight before a late winner from Lynn's Robbie Harris got Lynn, who only had two notable efforts on target all night, out of jail.
Josh Moreman had earlier cancelled out Spencer Tinkler's own goal for Lynn, who were second best over most areas of the pitch.
Setchell said: "We've got to make sure that a performance like Tuesday doesn't happen again.
"I treated the game more like a defeat and the only consolation in the end is that we managed to get the three points.
"There were at least ten players who didn't perform to the standards they've set recently.
"We will never play that bad and win again.
"I didn't set the team to go out and play like that and I'm sure the players didn't go out to perform like that and I will be looking for a vast improvement on Saturday."
Setchell added: "I'm bemused with that display.
"We looked leggy and clueless and didn't reach the levels that both the supporters and I as a manager demand.
�We didn't get the balance right of working hard and passing the ball.
�With Deeping making it very difficult for us and closing us down, we took the easy option and knocked it long, which is something I don't want from my players.�
Only the woodwork (twice), wayward finishing and some fine saves from Alex Street saved Lynn from an humiliating home defeat.
The attendance of 425 was the lowest for a league game at The Walks for 16 years when 367 saw Stourbridge visit in the last match of the 1995 campaign.
Defender Jordan Yong has become Lynn's latest injury concern ahead of tomorrow's game after being substituted early against Deeping with a viral infection.
Yong, who has been prescribed antibiotics, joins both Ross Watson and Defty on the sidelines.
Setchell said is it time for Lynn's fringe players to step up to the plate.
�There's nothing wrong with the squad we've got, but the players coming in have got to prove that they can fill the boots of the likes of Jack Defty and Ross Watson.�
|King's Lynn Town: Street, Bexfield, Yong (White), Wall, Buhlemann, Hughes, Spriggs, L Thurlbourne, Harris, Beaumont (Moriera), J Thurlbourne (Coe).