The singer, who has supported the Rams since he was four, was being filmed at Pride Park for a new film being made about the boy-band.
The film is being directed by Morgan Spurlock, who is the documentary maker behind Supersize Me, where he ate nothing but fast food for 30 days to see what effect it had on his health.
Niall had a kick-about on the pitch with some of his friends before the game kicked off, but no other members of the group were there.
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A planning application has been sent to the city council, despite some concerns that it would be a "particularly unsuitable location".
Clear and dry.
Showers, wintry on hills, with cold winds. Sometimes sunny.