Mark Ruffalo is being lined up to join Steve Carell and Channing Tatum in 'Foxcatcher'.

The 'Marvel Avengers Assemble' actor is in talks to play real life seven-time world and Olympic wrestler Dave Schultz who was shot by Steve's character John du Pont, a paranoid schizophrenic and heir to the du Pont chemical Fortune in the Bennett Miller directed movie.

After building a wrestling training facility in Pennsylvania - the titular Foxcatcher - du Pont murdered the wrestler on the premises in 1996 before being arrested and sent to prison, where he died last year.

Police never established a motive for the crime, which was witnessed by Schultz's wife and du Pont's head of security. After the shooting, du Pont barricaded himself in his mansion for two days while he negotiated his surrender over the phone.

Channing is attached to play Mark Schultz, David's younger brother who was also an Olympic champion wrestler.

'Moneyball' director Miller has reportedly been developing the independent movie for several years and has lined up 'Eternal Sunshine of the Spotless Mind' producer and 'Capote' writers E. Max Frye and Dan Futterman to work with him.