Macheda never had a chance to record a hat-trick on his home debut after being substituted 20 minutes from time.
But Dickov said after the 2-2 home draw with Nottingham Forest: "He's not had a lot of games recently and we had to bring him off.
"But the boy is going to be a top player. He came here when he had a chance to join bigger clubs because he just wants to play football.
"He's been unlucky with some of the clubs he's been at on loan. I think one of them lost their manager soon after he arrived so I'm just happy to still be here."
Dickov added: "Joking apart I think he will maybe take three or four games to settle in before we see the best of him.
"There's a lot more to come from him - I'm certain of that."