Cech has fallen below Thibaut Courtois in the pecking order at Stamford Bridge and made only seven appearances in the Barclays Premier League last season.
The 33-year-old has one year remaining on his contract and is reportedly attracting interest from a number of clubs including Arsenal.
Mourinho is reluctant to let Cech join the Gunners and suggested he may even demand a player in exchange if the veteran is allowed to leave.
"Every club that is interested in Petr, I can find a player that I like in that team too," said Mourinho, speaking at the launch of BT Sport's European football coverage.
"My answer is not important
My answer is not important because the owner is the owner, he is the person with the perspective I admire a lot, respect a lot.
"He respects a lot of people who do important things for him.
"Since 2004 to 2014-15, 10 years of success with the club, 10 years of unbelievable behaviour
I will have to accept any decision that the owner has.
"I'm different
I have the same respect for Petr that everybody at the club has, but my answer would be, no way
If the answer is different I will accept that."
Chelsea finished eight points clear of Manchester City at the top of the table but the Blues disappointed in the Champions League, where they were beaten by Paris St Germain in the last 16.
Manchester United, Manchester City and Arsenal are all expected to spend significant money on transfers this summer and Mourinho believes he needs three new players to stay ahead.
"We have to improve
If we have the same team the other teams will be better than us," Mourinho said.
"If I keep Eden Hazard, Nemanja Matic, Branislav Ivanovic, Diego Costa and Cesc Fabregas - for us that's the first target
"I think we need three (new) players
A striker because we lost our legend (Didier Drogba), a defender and a midfield player.
"(It will) give a little bit more competitiveness to the squad, bring some new blood in, put some players a little bit under pressure.
"They know they have someone waiting, I need that to support my way of working.
"Now they're the champions I need that but basically the same squad, the same team, the same manager and stability in the club."
Source : PA
Source: PA