Daniel Stendel has called on his experienced Hearts players to show more responsibility and take the lead in restoring confidence.
The German was taken aback at the lack of belief as Hearts lost at home to St Johnstone on Saturday in his first match in charge to leave them level on points with bottom club Hamilton in the Ladbrokes Premiership.
Stendel feels low expectations could work in their favour when they host leaders Celtic on Wednesday.
But he wants his established internationals such as Glenn Whelan and Christophe Berra to show the way in playing with confidence after noting 17-year-old Aaron Hickey was the bravest player on the ball on Saturday.
The former Hannover 96 and Barnsley manager said: "I didn't expect that the confidence would be so low. I hoped I could change it quicker but they didn't lose it the previous week, it was over a long time. I hope we don't need so much time to change it.
"The advantage is the expectation on Wednesday is not so high. As we say in Germany, we can only win."
Stendel added: "The main thing at the moment is not the style, the main thing is to change the heads. I am positive, I like to change things, I like to look forward and I want to bring this into the group.
"I have no idea what has happened but I have had some talks with players, some experienced players with a lot of professional games in their careers, not 20 or 25, and they cannot explain whey they feel so low in confidence.
"It's crazy that our youngest player had the most confidence on the pitch but we can change it.
"I think when Steven Naismith comes back he will give other players confidence. We need some individual players to have more confidence on the pitch, to ask for balls, to take more responsibility. This is the start to change things.
"When you look at the squad and the names and experience, you think you can talk and get some information on what has happened. But it's not too easy to get information because sometimes I have the feeling from the players they don't really know why they have lost confidence.
"When you have played 400 games in professional football and played for big clubs in England, when things don't work in a game like Saturday, what can happen?
"You have had a career before. The supporters are not happy, yes, you can blame this a bit but play your game. After this go home and next week it's the next game and in two years you have stopped your career. Nothing will happen.
"When you are 20 you want to have a career and play successful football and play every week, then you have a little pressure to play without mistakes.
"But not when you are 30, 32, 33, whatever. Come on, play for me, make a mistake, it doesn't matter, ask for the next ball. This is what we need.
"I know Glenn Whelan can take more responsibility on the pitch, and Christophe, we have a lot of players who can take more responsibility."