Brad Pitt was "obsessed" with making 'Moneyball'

Brad Pitt has revealed that he was "obsessed" with making Moneyball.

The actor, who was first attached to the project in 2008, said that he was determined to see the 2003 Michael Lewis book make it to the big screen, saying that he "couldn't let [the film] go".

"I saw it as a story about justice," Pitt told New York Magazine. "How is a team with a $40 million payroll going to compete with a team with a $140 million payroll and another $100 million in reserves? Any talent they grow is going to get poached by the rich teams. That became really interesting to me."

The film, which is based on a true story, centres on the Oakland baseball team's general manager Billy Beane's attempt to form a baseball club on a budget through the use of computer-generated analysis to draft his team's players.

In March, Pitt's Moneyball co-star Chris Pratt described the actor as a "down-to-earth normal guy", saying that he is "exactly like what you would hope".

Pitt is currently in negotiations to play an assassin in The Gray Man, a thriller based on the popular Mark Greaney novel of the same name.

Moneyball opens on September 23 in the US and on November 25 in the UK.

Watch the trailer for Moneyball below: