Both players were with the club during Warnock's previous time in charge.
He told the London Evening Standard: "They have Palace in their hearts and the fans will relate to them. It wasn't a case of panicking.
"Wilfried has something to prove. It will make such a difference that the fans are behind him. At Man United they don't seem to have time for the youngsters but he won't find that a problem here.
"It is one of the reasons why I brought Andy back to the club, not just for playing but pushing people to get into the first team. I asked him if he would do a bit of coaching with the strikers and he's enjoying it. We have Fraizer Campbell, Dwight Gayle and Zaha and they're all young lads with a lot to learn. He is the ideal person to teach them a few things."
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