The Belgium goalkeeper initially played on following his collision with Arsenal forward Alexis Sanchez before being replaced by Petr Cech and leaving the stadium for precautionary tests at a hospital.
The decision left the Premier League regulations on head injuries facing further scrutiny amid concerns that clubs have too much say in whether a player can continue or not.
"Doctor Biosca (Chelsea's medical director Paco Biosca) says there's nothing to be too much worried about," said Mourinho, after confirming Courtois had gone for tests.
"On the bench I don't communicate with the doctors
I just get decisions
'Can he stay (on)?' 'Yes'; 'He has to leave'
'Okay'.
"I have no time and no medical qualities to discuss that.
"I was just worried for the kid (Courtois), not worried about the game and the performance.
"We have two of the best three goalkeepers in the world, so when one of them is injured and comes out and the other one comes in, no problem, no change in my heart beat.
"(I was) so confident that Petr could do once more a fantastic job for us."
Cech began the season as second choice after a decade in the first XI and made his 480th appearance for Chelsea, just his second as a substitute.
The 32-year-old plays wearing a rugby scrum cap after fracturing his skull against Reading in October 2006 in an incident which heightened medical procedures at football stadia.
Mourinho, who was unhappy with Cech's treatment eight years ago, believes Chelsea acted properly in relation to Courtois.
"I always tell them (Chelsea's medical team) when I'm on the bench I don't want to communicate with them," Mourinho said.
"I just want them to give me a decision and they gave me a decision
For me that's correct.
"The club doctor, or the club medical department to take control and the responsibility."
Source : PA
Source: PA