Speaking after seeing the Eagles lose 2-1 to Blue Square South side Welling, Freedman said he had learnt some lessons about his squad ahead of the forthcoming campaign.
He said: "The result was disappointing but this has taught me a few lessons about what players can do and what they can't do. It showed me that some of the young players are nowhere near ready for the first team and that we need more depth in the squad.
"We need to add to our squad to make us competitive in the Championship. We are way short in squad numbers. We need to add a left winger, possibly a right winger, a couple up top and maybe a centre-half."
Freedman gave run-outs to several trialists at Welling, including Tiago, Yogo and Jamie Proctor, while Jose Baxter, who has been training with Palace in recent weeks, also featured.
