In a small Italian café in Montreal, Marc Dos Santos sat stunned.



FC Porto, the team from Dos Santos’s hometown in Portugal where he moved as a young boy, was beating up on AS Monaco in the 2004 UEFA Champions League final.



The UEFA Champions League final is the most anticipated game of the international club soccer calendar every year, in large part because it is when the game’s most noteworthy stars make a name for themselves. But the team he was cheering for appeared bereft of a singular star. Nine of the 11 starters were from Portugal. No squad that has appeared in a Champions League final since then has had as many players from the club’s country of origin in their starting lineup.



“In today’s world for a team to win the Champions League with nine of their 11 players from Portugal, it’s almost impossible,” said Dos Santos.



It was an awakening for the then 27-year-old technical director at...