Johnny Manziel struggled in the NFL and a new documentary has shed some light on why that might have been.

Manziel's former agent, Erik Burkhardt, explains that he was hearing from general managers that Manziel "doesn't watch tape."

"Well, he's gotta watch some tape," Burkhardt replied. The response: "His iPad hours is zero point zero, zero."

The documentary then cuts to Manziel, who admits it himself. "Zero."