Daniel Stendel admits he faces a major task to restore his Hearts players' confidence after St Johnstone ruined his first match in charge.
Substitute Callum Hendry's 74th-minute header earned a 1-0 win at Tynecastle to move Saints off the foot of the Ladbrokes Premiership and leave Hearts level on points with new bottom side Hamilton.
Saints winger Michael O'Halloran missed the best chance of the first half and Hendry was denied by a brilliant stop from Zdenek Zlamal before converting the resulting corner.
Hearts struggled to create chances and the home fans soon got on their backs before booing at the final whistle.
Stendel said: "We have a lot of work to do. We all expected more.
"The players want to play better but the feeling is it's very difficult to change it, especially the composure to play and create chances in the final third. We were too nervous, too hectic in some situations and we didn't create enough chances.
"St Johnstone didn't play well but they had three or four big chances and that was so much more than us.
"I didn't expect it to be easy. I hoped it would be easier today but I learn.
"The first thing we tried in the last few days was to change things in the players' minds that we can play so much better. You can see it's not so easy."
Stendel felt his players too often resorted to long balls and felt it was telling that 17-year-old left-back Aaron Hickey was the bravest player in possession.
The former Barnsley manager said: "In the second half especially Hickey played very offensively, he tried to play cross balls and tried to get us in the front foot. It's a sign for all that the youngest player played with the most bravery."
St Johnstone manager Tommy Wright was rewarded for doing his homework on his counterpart as Saints recorded a first away win in the league in 2019.
Wright said: "We knew how they were going to play. I watched some Barnsley games and it was documented how they were going to play and we worked on trying to deal with that, in behind them as early as possible if they are going to press you as high up the pitch.
"We probably didn't do it well enough first half even though Michael should score, and second half the game opened up a bit more and we got more opportunities."
Wright added: "Callum has a habit now of nicking goals. He probably should have scored the one which led to the corner but he made up for it. It was great movement.
"Again, we knew they were going to be zonal and sometimes when you are zonal there is space to go and attack."
Stendel admitted his side had failed to grasp the new tactic.
"We changed to zonal marking but at this moment we are not concentrated enough," he said. "It was too easy. We will talk about this in the coming days but we need to defend better at set-pieces."