Swansea defender Federico Fernandez admits his friendship with Argentina teammate Angel Di Maria has been put to one side ahead of Manchester United's visit to the Liberty Stadium.
Fernandez says the entire Argentina World Cup squad stay in touch with each other and he is in regular contact with British football's most expensive import.
But Fernandez says the lines of communication have been cut this week as Swansea, 2-1 winners at Old Trafford on the opening day of the season in August, seek their first-ever league double over United on Saturday.
"All the Argentine World Cup players are on a WhatsApp group and we all keep in touch with each other," Fernandez said.
"We are always in contact sending each other messages.
"Angel is an old friend of mine but there has been no banter this week.
"He plays for a different team and if he was through on goal I would have to foul him."
Di Maria has had a curious start in English football since completing his record 59.7 million-pound move from Real Madrid in August.
The 27-year-old appeared instant value for money by scoring three times in his first five games, including a goal of the season contender at Leicester.
But Di Maria has since scored only once in 16 appearances, in a third-round FA Cup tie away to League One side Yeovil, with injuries partly responsible for curtailing his early promise.
United manager Louis van Gaal has also utilised him in a more central attacking role at times but Fernandez has no doubt that Di Maria is at his best when he operates out wide.
"His best position is when he is on the right and can cut inside, but he can play anywhere and have an impact," Fernandez said.
"Angel has lots of speed and attacks spaces but he is also capable of scoring a great goal, so you have to keep an eye on him.
"It will take Angel time at Manchester United as a lot of new players have arrived at the club and they are still all learning to play together.
"It is also very difficult for foreign players to come here as it is a faster league than they are used to and there is more intensity.
"But Angel is such a great player he won't have any problem becoming one of the greats of United."
Fernandez's own introduction to the Barclays Premier League following his 7 million pound switch from Napoli in August may have flown under the radar compared to that of his compatriot.
But the 25-year-old has certainly not disappointed as he has established a commanding centre-back partnership with skipper Ashley Williams to help keep Swansea in the top half of the table all season.
"I want to do my best for Swansea and stay in the Premier League for a long time," Fernandez said.
"It is sad that a player like [Wilfried] Bony has left but I want to help Swansea get more points and get further up the league.
"United are on a good run and in a good position in the league but that is an extra motivation for us to beat them.
"That's why you join the Premier League, to play against a great team with great players and this is our chance to show our talent and get a good result."