Drogba is expected to return to line up against Atletico Madrid tonight following his suspension for verbally abusing Norwegian referee Tom Henning Ovrebo at the end of their semi-final defeat at the hands of Barcelona last season.
Ovrebo turned down a string of Chelsea penalty appeals but Platini defended UEFA's handling of the controversy.
Platini has watched Drogba's foul-mouthed antics on video since and says he will be back better than before.
"What I saw on TV was the comportment of Didier," added Platini. "All the TV showed the insult of Drogba, not the decisions.
"I was like Drogba in the past when I saw an injustice as a player. But I don't know Drogba's mind.
"He took the decision that he felt was right for him. He was alone in thinking that.
"Drogba's a good guy. I know him very well. He understands now that he made a mistake. Everybody does. He will come back better, stronger."
Platini also stressed he is not involved in the process of refereeing appointments and claims he still does not know Ovrebo's identity.
"When I arrive at a stadium, I don't know the name of the referee," said Platini. "That's the decision of the independent committee of referees. I was not there at Chelsea. I didn't know the name of the referee and I still don't.
"I don't know whether the referee made a mistake or not. If it was a mistake, I will say 'it's not a mistake' because I have to defend the referees."