Swansea have conceded seven goals in their last two games following the 3-0 defeat at Newcastle United.
They have three Premier League games remaining but assistant coach Curtis says they are not already thinking about their summer break.
"Hopefully they will want to come back a lot stronger next week," Curtis said.
"It's certainly not the players thinking [about] the holidays.
"We certainly can't afford any more performances like that but that's nothing to do with safety. That's down to poor professional pride.
"We obviously wanted to push on. We've had two desperately poor performances and certainly this was the worst we've had for a long, long time."
Swansea, who host Liverpool next Sunday, reached the 40-point mark with a 1-0 win over Chelsea at the Liberty Stadium on 9 April.
But they suffered their worst defeat of the season at the King Power Stadium as Leicester City took another stride towards the Premier League title.
Riyad Mahrez took advantage of Ashley Williams' poor clearance to score with a composed finish before Leonardo Ulloa added a second.
Ulloa scrambled in the third goal from a loose ball on the hour before substitute Marc Albrighton sealed the win.
"We had such a bad start in terms of conceding those two poor goals from our point of view," Curtis added.
"After that it just sort of deteriorated.
"You've just got to look in the dressing room and everyone's heads are down and we're all desperately disappointed with the results and probably more so with the performance."
Alan Curtis insists Swansea City's players still have plenty to play for and have not switched off despite their 4-0 defeat at Leicester.