Spain coach Vicente del Bosque has been forced to act as a peacemaker in the national team camp ahead of La Roja's friendly clash with Chile after tensions boiled over between Real Madrid and Barcelona during the recent Spanish Super Cup.
Barcelona beat Madrid 3-2 in the second leg of the tournament on August 18 to secure a 5-4 aggregate victory after the match ended in a mass brawl that saw three players sent off.
Madrid coach Jose Mourinho poked Barcelona assistant coach Tito Vilanova in the eye in the final minutes of the match, allegedly in response to a series of provocations and insults from the Catalan bench.
The clashes revived tensions between players from the two clubs which erupted during the run of four "clasicos" towards the end of last season.
"The situation in the national team is at breaking point," Villarreal midfielder Santi Cazorla warned recently while Liverpool's Spanish keeper Pepe Reina said "the atmosphere in the squad has got a bit weird".
Barcelona and Madrid contribute 14 of the 24 players in Del Bosque's squad for Friday's friendly against Chile in Switzerland as well as the Euro 2012 qualifier against Liechtenstein four days later.
The Spain coach - himself a former Real Madrid player who also coached the club to two Champions League triumphs - has expressed concern that the tensions between the two teams were taking their toll on his squad.
"The day will come where we will ask ourselves why we were so stupid and childish," he said ahead of the two matches.
Spain lost their place at the top of FIFA's ranking for the first time since winning the World Cup in South Africa last year after going down 2-1 to Italy in a friendly on August 10.
After the Spanish Super Cup, Madrid goalkeeper and captain Iker Casillas telephoned Barcelona midfielder Xavi to make peace before the the next two Spain matches, a move that reportedly angered Mourinho.
The Portuguese coach left Casillas on the bench during Madrid's 2-1 defeat of Galatasaray in a friendly at the Santiago Bernabeu on August 25 in what sports daily Marca said was punishment for his telephone call to Xavi.
"Casillas can talk on the phone with anyone," Mourinho told reporters after the match when asked if he was angered by the keeper's move.
Del Bosque said the telephone call between Casillas and Xavi "must be something that usually happens between them."
"I don't know what Xavi and Casillas talked about, I have not noticed any distance between them. You have to look after football," he said during an interview with radio station Cadena COPE earlier this week.
Meanwhile, Madrid defender Sergio Ramos welcomed Casillas' move.
"We know Iker very well, he is our captain and his gesture was the right one," he said.
"We have to take advantage of this team because it would be a shame to waste this generation. The silliness stays on the pitch."
Even if tensions between the two sides abate, they are likely to flare again when the two giants of the Spanish game face off in the first "clasico" of this league season in December.