Courtois returned to the club from a three year spell at Atletico Madrid, in which he was twice named La Liga's best goalkeeper, and now Cech looks like playing second fiddle to the younger man.
And one place where this has not gone down well is in his home country, the Czech Republic.
Cech is the nations international captain and first-choice goalkeeper. They want to see him playing regularly week in week out and this latest development is big news in the country.
However one former Premier League goalkeeper and Czech number one does not think Cech needs to panic. Pavel Srnicek played over 150 games for Newcastle United during his two spells at the club - he also spent time at Portsmouth, Sheffield Wednesday and West Ham during his time in English football.
Now goalkeeping coach at Sparta Prague he told Czech media outlet Aktualne his thoughts on the issue, suggesting Cech should remain at Chelsea for the time being:
"He is in a situation in which in the life of a goalkeeper often occurs. I have alternated on previously experienced goalkeepers in the past. He [Iker Casillas] was playing in the Champions League, the Spanish Cup, so still played twenty games per season. Mourinho has to address in the sense that Peter gets a chance. Plus in England there is also two cups. We'll see how the situation will develop further."
He feels Cech should stay as he may play in a similar role to the one Iker Casillas did at Real Madrid under Mourinho, and he has a point.
With Chelsea in the Champions League, FA Cup and League Cup - and expected to get far in each - Cech could still play over 20 games as the club's 'cup goalkeeper' if Mourinho does give him that chance.
Whether that is enough for Cech to stick around remains to be seen.