The Newcastle Knights' team coach did not leave as scheduled for Sydney on grand final day, then took a different route from the one planned.
Hundreds of supporters had gathered along Wallsend streets to cheer the team on.
Earlier, at about 8.45am on Saturday, coach Justin Holbrook said grand final week's emotion would not overwhelm his players.
The Knights were aiming to cap a 12-month rise from the bottom of the standings to the brink of the NRL summit.
Less than 45 minutes after Holbrook's media conference, the build-up to the match took a troubling turn.
Players noticed something was wrong when their Sid Foggs coach failed to depart promptly, before it was diverted from the planned route.