Wickham sustained an anterior cruciate ligament knee injury in Palace's defeat at Swansea on Saturday and now requires an operation.
The club have so far refused to put a timescale on the 23-year-old's return but he seems set to miss the remainder of the current campaign.
The striker has since taken to Twitter to reveal his disappointment, and has vowed to return "stronger than before".
He tweeted: "I can't describe how devastated I am, but I will do all I can to be back on the pitch as soon as possible and stronger than before!"
Crystal Palace last week