Wickham, however, went some way towards redeeming himself after he scored the winner with a towering header in Sunday's FA Cup victory over Watford to book Palace's place in the final at Wembley next month.
"The manager's brought me in with a lot of expectation, which I know I've not lived up to. I've been injured a lot, but before I had my last injury I was back scoring goals and that's what I love doing," Wickham told British media.
Wickham has been touted as having a bright future ever since making his debut for Ipswich just 11 days after his 16th birthday. But he struggled to justify the 8 million pounds ($11.64 million) Sunderland paid for him in 2011 and, five years on, knows that he must add consistency to his game.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
"I've got to look after myself, think about my training, my recovery, my preparation, make sure (an injury) doesn't happen again, because I've scored and hopefully it can be a kick-start. I hope (I'm over my injuries) more than anyone."
Palace take on Manchester United in a repeat of the 1990 final, and Wickham played down the label of underdogs, citing Leicester City's progress this season.
"Look at Leicester, they're probably going to win the Premier League," Wickham said. "So we're not going to think about underdogs or top dogs, it's us against them."
Sixteenth-placed Palace travel to face relegation-threatened Newcastle United at St James' Park on Saturday.
(This version of the story spells out pounds reference, adds dollar conversion in fifth paragraph)
(Reporting by Shravanth Vijayakumar in Bengaluru and Neil Robinson in London; Editing by Mark Heinrich)
