Transformers: Age Of Extinction actor Jack Reynor is in talks to portray baseball star Josh Hamilton in Casey Affleck's new biopic.

Affleck will direct his own screenplay, adapted from Hamilton's memoir Beyond Belief: Finding The Strength To Come Back, and Reynor has emerged as the favourite to play the slugger, whose sports career was sidelined and almost ruined by his addiction to crack cocaine.

Hamilton cleaned up his act and became a superstar with the Texas Rangers in 2008. In 2010 he was named the Mvp of baseball's American League.