The Blues have seen two offers for the England striker turned down but Mourinho insists the Southwest Londoners will not end their pursuit just yet.
"I don't want Chelsea to do it before we go there," he said of the August 26 meeting at Old Trafford.
"Everybody in the club, in the board, they agree with me. They share that opinion.
"I think this period, by the ethical point of view, is a period where we're going to be quiet."