Unlike Mirra Andreeva, 'Call of Duty' gamers are famously unimpressed by Daniil Medvedev

WATCH: Daniil Medvedev rallied from a set down, and 4-2 down in the decider, to beat Alexander Shevchenko and advance in Madrid.

The next time you're playing 'Call of Duty' on your TeamSpeak server, listen closely—because a US Open champion might be on the other line.

After coming from a set down, and 4-2 down in the decider, to beat Alexander Shevchenko in the third round of the Mutua Madrid Open, avid video-gamer Danill Medvedev dished about one of his favorite off-court hobbies. But the 2021 US Open champion, who famously celebrated his triumph in New York with the 'L2 + left, dead fish' celebration made famous in FIFA video games, also let slip that fast-rising 22-year-old Shevchenko, who's knocked around 150 places off his ATP ranking in the last 12 months, is one of his gaming buddies.

But, Medvedev says, his most memorable moments online have actually come from chatting with anonymous gamers.

"Usually I play with my friends. You cannot actually hear the opponents. You can only talk to your friends. Actually, few times even in my life it happened that I'm playing with someone I don't know, so we start talking and he's like, 'What do you do?'," Medvedev said.

"So I tell him, Yeah, I play tennis. Then some of them are, like, 'Yeah, really?' Then if they ask, I tell them who I am and they never believe me."

And while gamers worldwide might not be impressed with Medvedev's resume, one of tennis' most talented teenagers certainly is. When told that Mirra Andreeva was starstruck by seeing him, as well as Andy Murray, on-site during her breakout Madrid run, he heaped praise on the now-16-year-old.

"Me, at 15, I was probably not even 300, top juniors. [It's] definitely impressive," Medvedev said. "When she won the first match, I didn't know her before, I actually knew her sister a little bit by the name, and I saw that she's like [No.] 160 in the world, 15 years old.

"I said to my coach, Wow, look. She beat Leylah Fernandez straightaway, finalist of a Slam. Then I think now she's the youngest to be in that stage of a Masters 1000.

"What an amazing result. I saw her few times, said hi ... We don't know each other that much. I actually didn't see her play, but I'm super impressed with the results. I just hope that she continues to play that way, because then there is no limit."