Mark Ruffalo, who is working with director Derek Cianfrance in the upcoming HBO mini-series, I Know This Much Is True, revealed he missed out on an opportunity to work in the latter's 2010 movie, Blue Valentine.

Ruffalo missed out on the Golden Globe-nominated role of Dean Pereira, which was later played by Ryan Gosling in the film that also starred Michelle Williams.

However, Ruffalo brought Cianfrance on board to direct all six episodes of the series, which is based on Wally Lamb's novel of the same name. The Avengers actor felt Cianfrance's "Rough and holy" style would be ideal for the story.

Revolving around two distinctively different twin brothers played by Mark Ruffalo, I Know This Much Is True is about a blue-collar Connecticut family's struggle with schizophrenia and loss.