I do a little bit wonder whether The Guardian means that Infantino is explaining to Trump that Infantino is not a member of the spanish national team ("I am not..."), or if he is explaining to Trump that Trump is not a member of the spanish national team ("you are not...").

Either way is ridiculous and a solid joke, to be clear. Infantino is 56 and Swiss-Italian, and surely even Trump's few remaining neurons would have remembered having the physical ability to run just a few hours prior.