Idrizaj, who made his Swans debut against Scunthorpe in the Carling Cup earlier this season, died during his sleep at his family home in Austria on Friday.
He made three further Championship appearances this season, but did not find the back of the net.
Huddersfield Town and Millwall's League One play-off semi-final remains finely balanced after a goalless draw in the first leg at the Galpharm Stadium.