The Belgium international suffered the blow in a collision with Alexis Sanchez during the 2-0 win at Stamford Bridge last Sunday, which left him dizzy and bleeding from one ear.
Courtois was initially cleared to continue by Chelsea doctor Eva Carneiro, but was withdrawn and replaced by Petr Cech more than 13 minutes later after his symptoms worsened.
Headway, a prominent charity that supports those suffering from brain injuries, questioned Chelsea's handling of the situation and whether the Premier League's new regulations - which dictate players must be substituted if a concussion is suspected - were adhered to.
But the 22-year-old, who played 90 minutes for Belgium in their 6-0 European qualifier win over Andorra on Friday, praised the work of his club's medical staff.
"The doctor of Chelsea did well, I think," Courtois told Sky Sports
"She asked me the questions she needed to ask and I could repeat immediately so I was feeling well and didn't have to come off.
"I didn't feel I was knocked out but I was hit
I didn't have a headache or anything, but after a few minutes I felt worse and worse.
"Then I started to feel a little dizzy and I couldn't see the ball any more and there was a little blood coming from my ear
Because I saw trouble, I went off.
"I know you have to be careful, but I was not really knocked out."
Courtois underwent a series of subsequent tests in hospital, which forced him to join up with Belgium a day later than the rest of the squad.
"I had some neck pains, dizziness, and headaches for a few days afterwards, so that's why I stayed in England," he added.
"I had neurological tests to see if my brain was responding correctly and, after it was okay, I travelled to Belgium."
Belgium face Bosnia-Herzegovina in their next Euro 2016 Group B qualifier on Monday, with Courtois set to start once more, and captain Vincent Kompany has also been given the all-clear after a knock.
Source : PA