The player was unhappy when he was substituted against Fenerbahce in the Champions League quarter-final clash on Wednesday night but Grant insists there is no problem between the pair.
"Frank is a very passionate player," said Grant. "He was very disappointed that Fenerbahce had equalised.
"I shook hands with Frank. I like passionate players. If his reaction was good or not, it is an internal matter.
"The discipline at Chelsea has been very good since I've been here. I speak with all the players, but I speak about the game and not something else.
"Everybody was disappointed. It was one of our best performances but we lost the game so he wanted to understand why, that's all."