Leeds boss Marcelo Bielsa has admitted there is a 'sense of doubt' around his team when results don't go their way.
The Whites were beaten 2-0 by Yorkshire rivals Sheffield Wednesday in front of a packed Elland Road crowd on Saturday.
Wednesday found themselves on the back foot during a first-half where the hosts enjoyed the better of the opportunities.
Patrick Bamford had a goal ruled out for offside while Jack Harrison came within inches of firing Leeds into the lead before the break.
They were punished for their lack of clinical edge in the 87th minute when Jacob Murphy beat Kiko Casilla at his near post.
Late into stoppage time, Atdhe Nuhiu wrapped up the points after Adam Reach found him unmarked inside the area.
Bielsa, whose side were knocked off the top of the Sky Bet Championship by West Brom as a result, admitted there was some doubt around his team when results don't go as hoped.
"Clearly this was a match which was very important to make a difference," he said.
"It is a defeat, but it is not a definitive match. It's a moment which was very important to get a good result.
"We controlled the game and missed a lot of chances but there are still loads of games to go.
"We didn't risk losing the ball in our half during 85 minutes, in this time we created chances to try to make a difference, we lost two balls in the last five minutes and the match was for them.
"This has happened a lot of times and we know that we have to protect ourselves in those situations.
"Around the team, if we don't get what we are looking for, it's like a sense of doubt, not the team, around the team.
"When things go well, everything is positive, everyone is happy around the team but when they are not in the way people are expecting, everyone is afraid.
"Clearly this was a very important match to try to make a difference."
Bielsa was keen to outline that he didn't feel it was the Leeds fans who turned negative when they found themselves struggling to create goal-scoring opportunities.
"The opposite," he stated. "Because they scored after we lost two clear chances.
"One for Harrison and one for Bamford and the stadium was supporting the team in this moment.
"The supporters felt the victory, the win was close in this moment."
The Leeds boss also admitted that he is still keen to bring in a striker during this transfer window.
United are a striker down after Eddie Nketiah was prematurely recalled from his season-long loan spell by Arsenal.
Che Adams, Billy Sharp, Dwight Gayle and Barnsley forward Cauley Woodrow have all been linked with a switch to West Yorkshire before the end of the month.
And Bielsa outlined that while another striker wasn't the reason they failed to secure victory, it is an area of the squad that needs another body.
"We have to fill the space that has been left by Eddie Nketiah going back to Arsenal," Bielsa added.
"The lack of having him on the bench is not something which cost us the game, but need to fill that place in the transfer window."