Belgium international Thibaut Courtois started in goal for the opening Premier League match at Burnley on Monday night, which the Blues won 3-1.
Mourinho feels there will be plenty of opportunities for both men in the campaign ahead, when Chelsea are expected to contest across all domestic and European competitions.
However, he believes there will be plenty of players in his squad besides Cech who get less game time than they would like this season.
"Petr Cech is a top professional, he is working as always, behaving as always, being a group man as always, being a Chelsea person as always," Mourinho said.
"Is he totally happy? I don't believe so, but it is not (just) him. It is everyone who didn't start the game (at Burnley)."
"This period is hard for them, for me, because it is a period with one match per week, so (for the) first three matches, they clearly feel that some are playing more and some don't.
"But (in) September, (there is the) Capital One Cup, Premier League, Champions League, three matches a week, everyone is playing, with rotation, resting and (tactical) decisions - so that is an easier period for them and an easier period for me in the sense of everybody feels much better.
"Now, when there is only one match per week, some are not playing and they feel (it) more, but Petr's behaviour is fantastic, and that is important."
Mourinho, whose side face Leicester on Saturday, is no stranger to having to make difficult selection decisions, following spells in charge of Inter Milan and Real Madrid before returning to Chelsea for a second spell in June 2013.
"If you win it is easier because victories bring happiness to everyone, not just those on the pitch," the Portuguese added.
"If you win, the week after a victory is a good week for everyone.
"If you play one match a week, it is easier for the players to feel they are the first option or second option, that you have given priority to someone.
"But when you play three matches a week, important matches after each other, everything becomes easier for me and for them, because they (all) play.
"For Chelsea, there is no competition more important than the other one because we want to compete in every one."
Mourinho, however, accepts there could come a point where players are allowed to seek more regular football elsewhere - but only if it is in the best interests of the club.
"We have to think about the players, and the players deserve respect and co-operation from us as a club, but the club is the most important thing," he said.
"For me, football is about club, team, players, managers, so I am the last one in the list.
"We cannot give players things and put them in front of the team or the club. It must always be the other way round.
"Every decision the first thing we think about is the club and the team - but obviously, if you can make it good for club, team and also players, that is the perfect situation."
Chelsea forward Fernando Torres has been linked with a move to Roma.
Mourinho, though, indicated there was unlikely to be much movement in his squad ahead of the transfer deadline on September 1.
"My club did a fantastic job, not just because they got what they need, but they did it in record time, the market for us could almost close July 31 instead of the end of August, so we are very calm," he said.
"The counting down clock you have on Sky Sports News all of the time, for us there is no 'tick tock'."
Mourinho is expecting new boys Leicester, who drew 2-2 with Everton on their long-awaited return to the top flight, to come to Stamford Bridge in positive mood.
"They are champions, so they come with that winning mentality from the previous season, with high expectations and motivations to play in the Premier League," he said.
"They know that every point is important in this league, especially for the teams that fight to keep in the division, so they are coming to try to get points."
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