For the second year in a row, Marcus Lattimore will start the regular season on the NFL's non-football injury list, he told reporters Monday.
Lattimore spent the entirely of his rookie season in 2013 on the same list, which is similar to the physically unable to perform list but used for players who cannot practice as a result of conditions unrelated to football competition.
The running back will miss at least the required six regular season games, according to ESPN's Adam Schefter, who cited a league source.
Lattimore sustained a gruesome knee injury during his 2012 college season at the University of South Carolina. Team doctors are still wary of this injury, but neither head coach Jim Harbaugh nor general manager Trent Baalke have said what specifically is keeping Lattimore out of action, the Sacramento Bee's Matt Barrows reported.
Harbaugh told reporters Lattimore was "not yet 100 percent ... more from a physical aspect than a mental," stoking speculation that Lattimore was improving psychologically after the horrific 2012 injury.
- Will Green