Sylvester Stallone has joined the cast of “Reach Me,” an indie drama written and directed by his “Cobra” co-star John Herzfeld.Stallone recently wrapped several days on the set of the pic, which stars rapper-turned-actor Nelly, Omari Hardwick, Elizabeth Henstridge, Danny Aiello and Rebekah Chaney, who is producing alongside Herzfeld, among others. Story follows a group of people who all have a connection to a self-help book authored by a reclusive former football coach. Details of Stallone’s supporting role are being kept under wraps. Herzfeld previously wrote and directed the Robert De Niro thriller “15 Minutes” and “2 Days in the Valley,” which launched the career of Oscar winner Charlize Theron. He most recently directed “The Death and Life of Bobby Z,” an indie pic starring Paul Walker, Laurence Fishburne and Olivia Wilde. Stallone, who most recently co-wrote and starred in “The Expendables 2,” will next be seen in Walter Hill’s “Bullet to the Head” and Summit’s action-thriller “The Tomb,” which pairs him with Arnold Schwarzenegger. He’s also set to star opposite Robert De Niro in WB’s upcoming boxing pic “Grudge Match.” Stallone is repped by WME and attorney Jacob A. Bloom.