But, without any real reason being offered at the time, the tie was mysteriously played three hours earlier than initially scheduled. The world champion has now revealed why the chess24 Legends of Chess clash was moved: football, or, more specifically, fantasy football.
Carlsen, 29, a once-in-a-generation chess talent, is not just a football fan but was that day in the running to win the English Premier League's official fantasy sports game, Fantasy Premier League (FPL), on the final day of the season.
"My opponent was playing from China. So, basically, we rescheduled it for an earlier time for me and a more convenient time for him," he tells CNN Sport's Don Riddell.
"And the other thing is that the tournament we were playing was basically organized by my own company so if you can't use your power to do that, I don't know what that power is useful for."
What began as a hobby -- a welcome distraction from the grueling demands of being a chess grandmaster -- has become an activity in which he now excels to a ludicrously impressive degree.
Since first entering the season-long contest in 2015 -- a player assembles a 15-man squad from a budget of £100 million ($128m), with their footballers' performances on the field translating to points off it -- Carlsen has posted superb scores.
He finished 85,781 (out of many millions) in his debut season, rose to 2,397 in 2017/18 before dropping to 24,105 in 2019 (by his own high standards, just finishing inside the top 200,000 in the world in 2017 was nothing to write home about).
But it was this most recent FPL season where Carlsen picked up global coverage. Just before Christmas -- traditionally the time in actual football when the likeliest contenders for the title become tough to dislodge -- the Norwegian was in top spot in the fantasy version of the game.
He took to Twitter to point out that his "bio needed an update" with it now reading: "World Chess Champion. The highest ranked chess player in the world. Former (live) #1 Fantasy Premier League player."
Ultimately, Carlsen could not match the form of eventual champion Liverpool, which was top of the actual league by the second week of the season and would never be caught. But, then again, Jurgen Klopp's men only had 19 teams to worry about, whereas Carlsen was competing against 7.6 million others.
Come July 26, Carlsen -- fourth in the standings and 12 points behind the leader before the final matches kicked off -- had a decent shot of winning FPL. Ultimately, he could not overhaul his rivals and finished a respectable 10th.
"I think finishing top 10 is obviously a huge part due to luck," Carlsen modestly says. "Of course, if you're playing well, you give yourself a much better chance of being lucky. For me, it's just an interest. I like watching the games, I like spending a little bit of time to consider what players I'm going to use ... I'm somebody who spends at least a little bit of time on it. I can think logically, and I've had a bit of luck. That's it."
But "that" -- as anybody who has attempted to crack FPL can clearly attest -- is not merely "it."
FPL players are forever trying to land upon the best formations, balancing big names such as Mohamed Salah (at time of writing, the joint-most expensive player in the game at $15m) with hidden gems who can be purchased at a fraction of the cost but are regular starters for their clubs.
As Carlsen does not tend to discuss this aspect of his life too often, his perspective serves multiple purposes.
Asked about his formation of choice, Carlsen says: "Usually in the past, I've been a believer of 3-4-3, but I think probably with all the options that are in midfield, you should play five midfielders. So either 5-4-1 or more probably 3-5-2."
And what does he believe is the ratio is between strategy and pure luck? "I don't think you can be lucky unless you have a basis of good strategy and tactics," Carlsen responds. "I think that fantasy is quite similar to poker in that sense. There is a considerable amount of luck in there in the short term, but not so much in the long term."
It is fascinating to hear Carlsen dismiss the notion that a chess, or fantasy football, player should be planning way in advance.
"Most of the time in chess, you'd only think a few moves ahead unless it's like a very, very small tree of variations," he explains. "And, to some extent, the same applies in fantasy, that you should plan a little bit ahead, but you should always be very, very flexible when it comes to changing your plans, depending on the new data that that arrives.
"You can lay out a plan for the rest of the game, or in fantasy you can lay out a plan for 10 rounds to come. But the chances that you're going to have to change them significantly are very, very high. That's my strategy in everything: You come up with micro plans and then adjust to the new circumstances."
Carlsen goes on to acknowledge that he is part of perhaps the smartest mini-league in the FPL universe, where entry is only granted to a select few grandmasters. "Truth be told, there isn't much competition in the grandmaster league, so they really need to step it up," he says about his 12 rivals, with a twinkle in his eye.
As for what would be the more significant accolade, world chess champion or winning FPL, it is possibly the only instance over the course of the conversation that the grandmaster finds himself in check.
"In terms of the bigger achievement, of course, it's world champion in chess. But in terms of what I would appreciate more, that's a much more difficult question. But it's very difficult. So if people expect me to finish top 10 again, that's going to take an extraordinary amount of luck."
In chess, as in life, as in Fantasy Premier League, it's good to be king.