New Delhi, July 18 -- Canadian wildfire smoke continues to create uncertainty ahead of Sunday's FIFA World Cup final between Spain and Argentina at MetLife Stadium in East Rutherford, New Jersey. Approximately 80,000 fans are expected to fill the open-air venue as both teams prepare for the biggest match in world football under conditions that remain difficult to predict.

Mikel Merino can already smell and see the smoke that has created hazy conditions across large parts of the US, including northern New Jersey. The Spain midfielder is doing his best not to let it become a distraction.

"For a game that is as important as a World Cup final, you have to be able to shut out external factors as much as possible," Merino said Friday. "Luckil...