Englishmen abroad...

Football's development towards being a game
 of mass appeal occurred at a time of great commercial enterprise.
 It was not just military ventures that took the English overseas, but trade, industry and the 
development of such infrastructural necessities as railways in the countries that were following
 in the wake of industrial development.
The same of course could be said of the Scots, particularly with regard to the development of 
South American football.  
This is not intended to be an exhaustive list, but merely to provide examples of the way in which
 Englishmen were involved in overseas football.

Many overseas clubs, as we have seen, were founded by Englishmen, usually keen amateurs such as    
Herbert Kilpin (Milan) or Dr James Richardson Spensley (Genoa), but sometimes  professionals such as Mark Nicholson, the former West Bromwich Albion player and FA Cup winner who was a founder of First Vienna Football Club 1894.

A number of Englishmen were actually capped by other countries.
The most extreme example of a national team fielding 'foreign' players  must surely have been Russia in their (second) 1912 encounter with Hungary, The team contained 5 Englishmen,  members of Moscow's British Sports Club.
William 'Vasily 'Charnock 

Arthur V. Parker
Arthur V. Parker
G. Newman
T. Lunn
Edward Thomas

A number of Englishmen represented Belgium:
Alphonse Wright (midfield, Racing Club de Bruxelles, Belgium 5 caps 1906-07)
Wright kept his British citizenship a secret from the Belgian football authorities.

 Georgy Hebdin (forward, Royale Union Saint-Gilloise, Belgium 12 caps 1908-20)
Initially kept his British citizenship a secret, but then satisfied FIFA's residency law.

Eric Thornton (goalkeeper, Léopold FC de Bruxelles, Belgium 2 caps 1905)
Thornton went to Belgium to study and represented  l'Université de Bruxelles in the 1900 Olympics. In 1907 he relocated to Antwerp and joined Beerschot AC.

Charley Stansfield  (forward, Vienna Cricket and Football Club,2 caps 1905)
A real dark horse, with no form as a footballer in his native UK, he scored 4 goals in an international for Austria in a 5:4 win over Hungary, Stansfield played for Vienna Cricket and Football Club and won 2 international caps. He was however, a gambler and a drinker. Cricketer sent him packing, back to England, ad he appears never to have played again. 

If you look at the Argentina line up that faced Uruguay on 21.10.06 the British/ European influence is obvious from the names of the players, many of whom were the sons of immigrants. 2 of the Argentina  players were actualy English born: 

Héctor J. Henman (inside forward, Alumni- 1 capHarold James Henman had traveled to South America with a South African touring side. He was, however, English born.
Wilfredo A. Stocks (winger, Belgrano- 1 cap) born in Nottingham, both parents English, moved to Argentina as a small boy. 

France (tenuous)
 I hesitate to include Charles Wilkes,  some sources claim he was born in the Chanel Islands and  adopted French citizenship, others record him as being born in Le' Harve. He played 4 times for France (1905-08).
Similarly Victor Sergent (Victor Bentall-Sergent) was born in England, but his father was French. The Racing club de France defender was capped 5 times by France (1907-13).