Caretaker manager Steve Agnew admitted he was shocked by Sheffield Wednesday's below-par showing against Hull City.
Two goals from Jarrod Bowen and one from substitute Fraizer Campbell condemned the Owls to a 3-0 defeat at the KCOM Stadium.
Wednesday were second best throughout and fell to their first defeat since Steve Bruce was named their new manager earlier this month.
Agnew, who is holding the fort until Bruce officially starts on February 1, told The Star: "There were things that I saw against Hull that surprised me but you can't forget these things because we are here to turn this football club around and move up the table and get where we ultimately want to get in the future.
"I think the players understand that and they have to be honest with themselves, move forward and get back to work and ready for the cup tie on Luton."
The Owls, backed by over 2,300 supporters in East Yorkshire, failed to muster a shot on target.
"We have not got to brush it under the carpet," said Agnew. "We will speak to the players and we have to be open and honest and we have to work together on this.
"We have look at the reasons why we lost. We were just miles off the pace and it is very difficult to put your finger on why and we need to find out.
"I don't think anybody can walk away from Hull thinking that was anywhere near what is required.
"We have to be brutally honest about it, roll our sleeves up and get to work and put a performance at Luton on Tuesday night."
The Owls face Luton in an FA Cup third round replay on Tuesday evening knowing the prize for the winner is a trip to Stamford Bridge to take on Premier League big guns Chelsea on Sunday, January 27.
Agnew, who has not ruled out the possibility of strengthening the squad, said: "There are some talented players in there; I wouldn’t change my mind on that in the dressing room but we have to find a balance, a style of play and a way of winning.
"There were certain stages within that (Hull) game and things don't always go for us but you have to find a way to stay in the game.
"When the second goal went in, we made it easy for the opposition. We lacked resilience to try and claw our way back."