No one knows exactly when Robert Griffin III will return to the field. But when it does happen, Coach Mike Shanahan said the Redskins’ quarterback will be much more focused on avoiding big hits.

“When you go from the collegiate level to the professional level, you don’t realize the speed of these guys,” Shanahan told Pro Football Talk’s Mike Florio this week at the NFL meetings in Phoenix. “He took a lot of unnecessary hits.”

Shanahan said Griffin III is working out six to eight hours a day as he rehabs from major knee surgery. The reigning offensive rookie of the year had the ACL and LCL in his right knee repaired by renowned orthopedic surgeon Dr. James Andrews on Jan. 9.

But that’s only part of what Griffin does with his time each day at Redskins Park. He’s also in the film room, dissecting each hit he absorbed and learning how to avoid a similar blow next season.

Griffin was injured twice while running the ball in 2012. He suffered a concussion against the Falcons when linebacker Sean Weatherspoon popped him with a clean hit as he attempted to scramble out of bounds. Then, eight games later, Griffin suffered a sprained LCL in his right knee when Ravens defensive end Haloti Ngata as he sprinted down the middle of the field.