The 19-year-old striker appeared as a half-time replacement for Steven Fletcher during the 2-1 defeat at Norwich and produced an impressive showing up front.
"It's been a long four or five months for me and it was great to be on the pitch," Wickham told safc.com.
"I've spoken to the gaffer before and he told me what I had to do, so I have worked my socks off in training and thankfully he had faith in me today.
"The manager has told me to hold the ball up and be more aggressive, and I've been doing that more in training and that's why my chance came.
"When I came on I thought I did that; now it's about getting that match sharpness."