"You have to accept any decision that the owner will have in relation to Petr, but I am different," Mourinho said at the launch of BT Sport's European football channel.
"I have the same respect for Petr that everyone at the club has, but my answer [if he can join Arsenal] would be no way. If he answer is different, then I will accept.
"My answer is not important to this question because the owner is a person with the perspective that I admire a lot. He respects people who do important things for him and since 2004 to 2014-15, he has given great service to the club, unbelievable behaviour."
Mourinho also said he may look to secure a swap deal with a Premier League rival, if Cech is to seal a move to Arsenal or Manchester United.
"For every club that is interested in Petr, I can find players in that team that I like too," he added.