Macheda never had a chance to record a hat-trick on his home debut after being substituted 20 minutes from time in the 2-2 draw with Nottingham Forest.
But Dickov said: "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."
Cohen scored with a powerful shot in the 40th minute and it needed another spectacular strike from Andy Reid to snatch a point nine minutes from time.
Dickov added: "We're possibly a little bit disappointed not to have three points after twice being in front but first and foremost it was a fantastic game of football between two teams that really wanted to win.
" I changed the side around because we wanted to be brave and bold and really go for it by playing three strikers.
"Some of the football we played against a top team that will be up there at the end of the season was magnificent and it shows we can be competitive and get better in this league."