If the Hatters achieve Premier League promotion with a victory over Coventry City in the Championship Play-off Final, Mpanzu will become the first player to go from non-league football to the top flight with the same team.
"Yeah man, not a lot of people do it," he told a press conference, then instantly realised his error.
"Well, nobody has done it yet," he laughed. "There's 90 minutes, one more game to go. (Hopefully) by Saturday, 7pm, we will be drinking some champagne."
Luton acquired the midfielder in 2013 on loan from West Ham United and in his 366 games since, he has become a cornerstone of the team as they climbed from non-league football in his first season to the Championship, with four years in League 2 and just one in League 1 along the way.
"Premier League is the most elite league in the world now. It's unbelievable credit to him that he can hopefully achieve that," said John Still (73), the former Luton manager who signed Mpanzu after meeting with him and his mum.
Mpanzu was not exactly sold on the club when he set eyes on Kenilworth Road, their shabby stadium that draws sneers from outsiders.
"I was like: aw, man," Mpanzu said, rubbing a hand over his face at the memory. "But listen, everything worked out in the end. It's been a journey since then."
The Hatters beat Sunderland 3-2 on aggregate in their play-off semi-final, reaching the final with a thrilling 2-0 win in front of a delirious crowd at Kenilworth Road, who celebrated as if promotion was already in the bag.
Mpanzu posted a video to fans, saying: "We've got one more - see you at Wembley."
Promotion would see Luton tie Wimbledon's record of going from non-league to the top flight in nine years.
