SANTA CLARA — Second-year running back Marcus Lattimore cleared another hurdle when he participated in the 49ers first round of organized team activities. Now he's eager to see how his right knee holds up during full-contact drills.

"It's just good to be back out on the field." Lattimore said Tuesday after he completed yet another practice without any setbacks from a dislocated knee and torn ligaments he suffered at South Carolina in 2012.

Lattimore is itching for more, though. He spent all of last season rehabilitating, away from full-team activities, and has yet to play in an NFL game of any kind.

Already he is looking forward to the 49ers exhibition season, when Lattimore can get back to taking a hand-off, looking for room to run and getting up after being tackled.

A portrait of San Francisco 49ers running back Marcus Lattimore, who has been recovering from his 2012 knee injury, on May 1, 2014 at the 49ers’
A portrait of San Francisco 49ers running back Marcus Lattimore, who has been recovering from his 2012 knee injury, on May 1, 2014 at the 49ers' practice field in Santa Clara. (Dai Sugano/Bay Area News Group) ( Dai Sugano )

"As soon as I play that first preseason game, take some hits and get back up, I'll be fine," Lattimore said.

In the interim, Lattimore said he is making sure that he plays with the proper mind-set. That entails cleansing his mind of the gruesome injury that ended his college career and not fearing another injury.

Forgive Lattimore if that takes time. In 2011, he tore the anterior cruciate ligament in his left knee during his sophomore season at South Carolina.

"Mentally I have to block out that (concern)," Lattimore said. "My knee is fine. I've worked hard; I've done all I can. All I can do is go out there and run and show the coaches that I'm getting better every day and getting ready."

Lattimore is expected to compete for playing time behind starter Frank Gore against the likes of Kendall Hunter and LaMichael James.

Follow Steve Corkran on Twitter at twitter.com/CorkOnTheNFL.