On a freezing night in Prague, the Dutchman pulled all the strings in a rotated Barca team, driving forward and making tackles across the pitch.
Ironically, even in this game, where he looked powerful and poised, it will be Fermin Lopez who will grab the headlines after netting a first-half brace.
This is the conundrum facing the captain on the night. He quietly goes about his work with a minimum of fuss, and that in itself can be easy to expect from him.
One person who took great pride in his performance on Wednesday night was manager Hansi Flick. Speaking in the post-match press conference, the Barca coach told Flashscore: "I think, today, Frenkie played amazing.
"It's unbelievable, he's a great captain, I really love what I saw from him today, and he's so important for the team. He played at an unbelievable level.
"Not only in the offense, this is what we know from him, but also in the defence, and this is amazing, really amazing."
De Jong's best moment on the night was the assist for Fermin's first goal. His weight of pass was perfect to slip in the Spaniard - it was reminiscent of Barcelona teams of old, where they would break the line of a packed defence with one sumptuous pass.
The passes were one thing, but what caught the eye was his ambition. He received the ball on the half-turn a handful of times on the night in Prague, and each time was prepared to drive with the ball. A 40-yard through ball that almost found its way to Raphinha typified his evening. It had the air of someone trying to open the game up, rather than always controlling it.
He is one of the old guard now at the Camp Nou. Signed in 2019, and having played with Lionel Messi when he first arrived, De Jong has that classic Barca DNA running through his veins, but as the team has evolved, so has he.
In his box-to-box role against Slavia, who went man-for-man for much of the game, he was able to break the lines, drive forward with the ball and attempt a direct pass to give his team a chance to score. In the win, he created four big chances and had a 90% pass completion over the 90 minutes.
He nearly had a goal to boot, which would have capped off the fine display, only for it to be ruled out for offside.
That fearlessness to find the final pass is something that Dutch football expert and Flashscore journalist, Finley Crebolder, believes is something that has improved in his game.
He explained: "He's become a lot more assertive as a player and as a person, he presses harder, wins the ball back more and has become much more of a leader.
"He's even more forceful in the final third, takes a few more risks rather than just keeping things ticking over."
That tracks with the numbers, too. The pass to Fermin was his fourth assist of the campaign, just one behind his season record at Barcelona, with plenty of games to go. Not content with sitting deep and allowing sideways passes to take over his game, he's pushing forward even more.
The tackling aspect has gotten him into trouble in recent weeks, however. Sent off in the Spanish Super Cup final victory over Real Madrid, and booked against Slavia, which rules him out of the final League Phase game against Copenhagen, he will want to limit those disciplinary issues so he doesn't miss out on big games through suspension.
Barcelona face an uphill battle with a vulnerable backline to go deep in the Champions League this season, but if they are, De Jong is the player who knits it all together for them. Keeping him in good form feels pivotal to their success as we enter the business end of the campaign.
