The pair clashed in training last week.
"As far as I am concerned, the case is closed," said Mihajlovic.
"He got it wrong and apologised. I hope he understood the situation and is at our disposal. In fact, it's better that this happened straight away, because at least he understood how things work at Samp.
"I have no ill feelings, but he will play when I see he is at the same level as his teammates. I don't think I am snubbing his career by saying that. Every player is different, but the rules are the same for everyone.
"Believe me, when Eto'o scores his first goal for Sampdoria, I will be even happier than him! He's always smiling and is very humble with the lads in the locker room too."