The running back, who was a fourth-round draft pick earlier this year, sustained a dislocated knee during his final season in college.
The 21-year-old told NFL Total Access: "I did a lot this off-season. You know, we come back in late July.
"Been running sprints, you know, got a chance to get in there with the guys a little bit, that felt good.
"Probably won't do training camp. You know, just on course with the trainer and my doctor. Get a chance to practice mid-season and see what happens."
Lattimore signed a four-year contract with the 49ers following the draft.