Kalidou Koulibaly had a very impressive debut for Chelsea.

The Senegalese defender was signed for around £33 million this summer in an attempt to fill the void left by Antonio Rudiger.

Some would say it's a lot of money to spend on a 31-year-old. Those people probably haven't watched the former Napoli man too closely.

Because, despite his advancing years, Koulibaly is still one of the best defenders in world football.

He showed that on Saturday evening as Chelsea triumphed 1-0 over Everton at Goodison Park.

And it seems he's already a favourite amongst the fanbase.

That's because the travelling away fans could be heard singing a new chant for the defender.

While Koulibaly will no doubt appreciate the chant, it's fair to say the song hasn't gone down well on social media.

Why?

Well, have a listen and you'll soon know why...

VIDEO: Chelsea fans' new chant for Koulibaly

"I wanna know, he's from Senegal..."

Sorry, what?

What does that even mean? I want to know, he's from Senegal. What do you want to know? The fact he's from Senegal? It just doesn't make sense.

Unsurprisingly, the chant is being slated online. Check out the best reaction:

Hopefully, in a few weeks, Chelsea fans will have given the new chant a bit more thought and perhaps changed the lyrics slightly.

After Chelsea announced the signing of Koulibaly last month, Thomas Tuchel couldn't hide his delight.

“We followed him for many years," he said. "Me personally and my staff followed him for many years and tried many times and were never successful because it is very hard to get players from Napoli, who are well known for the fact that they keep their squad together.

“He’s a leader. We had good information about him from Mendy and from Jorginho. We got the same feedback, a fantastic guy, a leader in the dressing room, calm, a role model. 

“When you dig in and start looking at his games, analysing his games, you see the quality in defending, the quality in body positioning, his timing of defending.

“He uses both feet for build-up, he is confident, mobile and very experienced. When we had the chance, we went for it. It was our top priority. Very happy that he is with us.”