Following the soon to be departed Diego Costa in January, Courtois spoke to Standard Sport about the new arrival Alvaro Morata.
With Costa being a close friend of Courtois', the Belgium said it's time to move on and now Morata has come in, they are pleased with how he is doing so far.
"Alvaro Morata has come in and he is doing his job and we are happy with that."
On Saturday against Stoke he scored his first Chelsea hat-trick, and he has looked impressive ever since he joined the club in July.
"We know Alvaro is a top striker, we know he has ability and I am very happy for him that he scored a hat-trick. It's good for him and all of the team, Stoke away is a very hard game." Courtois said.
Reflecting on recent results at the bet365 Stadium, the Belgium added: "Last year we won here in the last-minute, Arsenal lost here this season, Manchester United struggled here too. So to score four goals, we must be pleased."
The keeper made sure to add that he has been consistent from the off, and he is making a real difference to the side who are looking to retain their title.
"But it's not just his hat-trick against Stoke, he has been scoring from the beginning. He is feeling good, strikers always do when they're scoring. He has scored a few important ones for us already."
With Chelsea set to play Atletico on Wednesday, the Chelsea goalkeeper said Morata will be used to the treatment he will get from Atleti fans after his time at arch rivals Real Madrid.
"He will get a different reception to me! Alvaro played a lot of games against Atletico, but for him it will be a big game against his rival of all time."