Palace boss happy with Portsmouth's Songo'o
Warnock said: "I saw him in the reserves last week and it was time to give him another chance.
"I told him he could go back to Portsmouth but he came and asked me if he could fight for his place and show what he could do.
"And he did that. He was part of a team, he was no frills but he did what I expect players like him to do."