Palace's 1-0 defeat at Liverpool represented a big improvement on a 3-0 home defeat against Huddersfield the previous weekend, but de Boer would still like more players at the club.
"We are still looking to see if there is real quality to add to our squad. If there is real quality rather than panic buys, we won't hesitate," said the Dutchman.
"I said to them if they play with this kind of intensity and discipline the results will come. To lose 1-0 is very disappointing because we deserve more but I am convinced if we show this every week the results will come."