Director Robert Siegel has said that between takes in the strip club, while other members of cast and crew were enjoying the company of dancers, actor Patton Oswalt was watching episodes of John Adams - Freiheit für Amerika (2008) on his iPod in a private room.
Patton Oswalt and Kevin Corrigan were unable to improvise cheers during football games because neither of them knew any football terminology. Robert Siegel had to give them line readings.
When talking about the Giants, Paul always uses the pronoun "we" when talking about the team winning, and "they" when talking about them losing.
Every football player referenced in the film by any of the characters or the radio host is a real NFL player other than Quantrell Bishop.
Originally planned to be a straight-forward comedy titled "Paul Aufiero" but Robert Siegel personally re-wrote his script into a drama.