The England captain could now face up to three months on the sidelines due to a injury.
Kalou said: “I told Emmanuel that it was a red card because he did it on purpose, but he denied that.
“He said sorry to John. He didn’t mean to do it but to apologise was a nice thing to do.
“John will be a big loss for us and is very important to the squad. We will miss him and it will be difficult to do it without him but we have the players.”