Enner Valencia will put club before country when he comes up against Ecuador teammate Jefferson Montero on Sunday.
Valencia and Montero were part of the Amarillos squad which drew 2-2 with England in June before reaching the second round of the FIFA World Cup.
The pair previously both came through the ranks at leading Ecuadorean club Emelec, where Montero burst through as a teenager in 2008 and Valencia established himself as a first-team regular in 2010.
The duo's form for Emelec earned them big-money moves - Montero to Ecuadorean side Independiente, Spanish club Villarreal and Mexucan outfit Morelia, and Valencia to Mexican side Pachuca - before they each impressed in Brazil this summer.
On 24 July, Montero joined Swansea City, and five days later West Ham United swooped for Valencia. The pair have both made encouraging starts to their careers in the Barclays Premier League, with Montero impressing as a substitute before breaking into the starting XI at the end of October, and Valencia scoring a couple of wonder goals and forging an eye-catching partnership with Diafra Sakho.
"Jefferson is a very good person and as a player he has shown what he is capable of and is doing really well in the Premier League," Valencia confirmed.
"We both played in Emelec, which is a club which has very good young players and has sold many players to European clubs in recent years."
On Sunday, the pair will be on opposite sides when the Hammers entertain the Swans at the Boleyn Ground, and Valencia insists his loyalty to his compatriot will mean nothing for 90 minutes.
"We played together against England and at the World Cup and that was good, but now we are on opposite teams and we will be doing our best for them. We will see what happens and then we will keep being friends after the game!"
The Ecuador duo celebrate Valencia's goal against England
Valencia returned to the squad for the midweek win at West Bromwich Albion after missing two games with a knee injury, and is hoping to be involved again on Sunday.
"I'm happy to be back. It was good to play a game again and it is good to be ready for the squad to play against Swansea.
"We have had a few injuries in the last few weeks to important players for the team, but the people who came into the starting XI and as substitutes have done well."
While Valencia has experienced the 100mph nature of the Barclays Premier League in his first few months in England, he is likely to see a more familiar style of football when West Ham take on a possession-based Swansea team.
"They are a team that like to keep possession of the ball and they will try to keep it and build play. What we have to do is press them in their half of the pitch and try to get the ball and play our game and hopefully we will do our best."
*A limited number of tickets remain available for Sunday's 1.30pm kick-off v Swansea City at the Boleyn Ground. To secure your seat now, click on the graphic below.