Wickham led the Under 17s to European Championship glory in the summer and was called up by Stuart Pearce after Danny Welbeck and Tom Cleverley pulled out.
The forward, who along with Chelsea's Josh McEachran is still just 17, is valued at £10million and he needed only one training session to impress his qualities upon the manager and his team-mates.
"Connor is a target man with a touch more," said Pearce, confirming that the striker will play at some stage.
"He holds the ball up well, he's fantastic in the air. It's like with Peter Crouch. If you say he's just a target man, you are doing him a disservice.
"His eye for the game is quite good. I have to temper that with the fact that Connor may be up to five years younger than some here. I have to be careful with him. He's a clever player and clever players find a way to cope."