Ferran Torres settled the contest with a 106th-minute strike as Spain won 1-0 in extra time at MetLife Stadium in New Jersey, a result that ended Argentina's reign as world champions after a frustrating night in which Lionel Scaloni's side managed only two shots, neither on target, across 120 minutes, and had Enzo Fernandez sent off for a second yellow card late on.
According to Marca, the flashpoint stemmed from comments Spain defender Aymeric Laporte had made in the days before the final about refereeing standards during Argentina's run to the showpiece.
"I'm not worried at all about physical play as long as it's part of football. If the referee does his job, I have no problem with it," Laporte had said. "It's true that in recent matches we've seen things that have surprised us, situations that have been allowed to go unpunished. Especially with Argentina, which is a team that likes to leave little messages with its challenges.
"That shouldn't be allowed in football, particularly in tournaments of this magnitude, because it can unsettle you and make you lose your composure. It's the referee's job to keep the game under control so the match doesn't get away from him.
"If one or two players are allowed to do what they want, the game will become chaotic. Since the tournament began, we have been a fair team in that regard."
Those comments were still fresh in Otamendi's mind when he came face to face with Rodri after the final whistle.
"Start talking less, idiot. You guys spent the whole week crying," Otamendi said. "You and Laporte, both of you, that's now how it's done. You were crying to the referees all week, my friend."
Rodri, left stunned by the outburst, asked the River Plate defender what he was talking about.
"Laporte. Didn't you see what he said this week?" Otamendi replied.
The confrontation was one of several ugly scenes at full-time, with Nahuel Molina involved in a physical altercation with Rodri, while Leandro Paredes was sent off after grabbing Eric Garcia by the neck and flooring Gavi. Otamendi and Rodri spent a season together at Manchester City until the Argentine's departure in 2020, while Laporte also overlapped with both players at the Etihad before leaving the club in 2023.
The scenes capped a bruising night for Argentina, who had gone into the final chasing back-to-back World Cup titles but were unable to find a way past a Spain side that finished the tournament having conceded just once.
Rodri, who was later named the competition's best player, walked away from the confrontation with Otamendi rather than continuing the exchange, leaving the Argentine's outburst to stand as one of the enduring images of a tense and, at times, ill-tempered finale in New Jersey.