In the end he went with the latter. Sitting Courtois on the bench after three seasons at Atletico Madrid, where he soon established himself as one of Spain's best goalkeepers, would have risked losing the talented stopper, a risk Mourinho could not afford to take.
So far Courtois has not yet disappointed Mourinho or the fans with his performances - while Cech has had to get used to the unusual position of sitting on the bench, enviously watching on.
But while tongues are wagging and pundits are raving about Courtois, one former Premier League goalkeeper has issued a word of caution on the young stopper.
David Seaman is considered an Arsenal legend and played over 400 league games for the club in his 13 year spell in North London.
When speaking to former team-mate Ian Wright's radio show this weekend he insisted that until Courtois has come out the other end of a dip in form, that praise should be mooted.
He is reported to have said:
“Courtois has still got a few more seasons to catch up to what Petr Cech did."
Of course Seaman is right. He does not doubt the fact that Courtois has the potential to be as good as Cech, but until he does it consistently over the next two to three seasons at Chelsea he can not yet be considered on the same level as the legend he is currently consigning to the bench.