Spanish newspaper Marca are among those reporting an alleged incident between the normally-even-tempered Argentinean and Alvaro Arbeloa. The four-time Ballon d'Or winner supposedly confronted the Spanish star in front of his pregnant wife and daughter, and dished out a whole host of insults before being led away by a Barcelona employee. Insidespanishfootball.com have more detail:
Messi confronted Arbeloa, who was with his wife and daughter in their car, and had several heated words for the Spanish international before the Argentine was led away by a Barcelona employee.
Arbeloa and Messi had several exchanges throughout the match, with both covering their mouths to hide their words from the cameras.
Messi's anger appeared to stem from an incident in the game during which he was slapped by Arbeloa and then pushed in the face by Xabi Alonso (see the video above). The diminutive Argentinean refused to shake hands with Alonso after the match, apparently citing his lack of sportsmanlike conduct during the game.
Marca, meanwhile, say that many Real Madrid squad members are "quite upset" with Messi. To be fair though, a certain Portuguese forward was already quite upset with Messi's general existence.