Felix Magath said Fulham's home form will decide if they beat the drop after suffering a 3-1 defeat at Cardiff City Stadium on Saturday.
Magath admitted confidence is low amongst his rock-bottom Fulham outfit who have not picked up three points since New Year's Day - a run of eight games.
Lewis Holtby's close-range finish levelled the match just before the hour mark to give his side hope of taking at least a point from south Wales, but they held out for just eight minutes before Caulker's second.
And having received a frosty reception from their travelling supporters at the final whistle Mageth knows he faces a tough task to lift his squad for the visit of Newcastle.
"The second goal breaks us," he said. "If you come back into the game especially in an away game, and you score, then you are very eager to get more and the second goal came too early. After that we are not able to come back.
"Our chances are worse than before. We have to win our home games, that is the most important thing. The next game is a home game against Newcastle and we need three points.
"When you are in the situation when you are losing you have not enough confidence to take unfortunate situations as happened here."
Magath made four changes but two selections in particular raised eyebrows in the away end with Kostas Mitroglou thrown into the starting line-up for the first time since arriving from Greece for a club-record fee to partner untried teenage Cauley Woodrow on his Fulham debut.
But the German rejected suggestions that handing a 19-year-old, whose last competitive action came during a loan spell at Southend in January, was a risk.
"I see no gamble in it because he is a very talented player and I was satisfied with him," the German said.
"He did a lot of work for the team and I was very satisfied."
