49ers running back Christian McCaffrey has two more weeks on injured reserve, but after two weeks of rest, he’s readying to see what he can do in rehab.

“I think we’ll get a better idea here over the next couple of weeks,” coach Kyle Shanahan said on his weekly radio appearance on KNBR, via David Bonilla of 49erswebzone.com. “The whole point of putting him on IR is to guarantee that we couldn’t do anything for at least four weeks, and two weeks into it, the whole point was just to rest him for two weeks and not do that.

“And now, we’re going to start hitting the rehab harder and trying to get him back into football stuff and see how it responds. So we’ll see how he responds here. We’ve let him rest here for a couple of weeks.”

The 49ers placed McCaffrey on injured reserve Sept. 14 with a lingering calf injury and Achilles tendinitis. He cannot return until at least Week 6.

Earlier this week, Shanahan confirmed McCaffrey traveled to Germany over the weekend to consult a specialist about the injury.

“Christian’s just seeing every specialist he can, doing all the little stuff that Christian does more than anybody I’ve ever been around,” Shanahan said Thursday. “He is of full-time commitment to everything for his body year-round. And so, he’s been doing that stuff while not pushing it hard in rehab.

“And now, we’ll probably turn it up here in the next couple of weeks. I know he still has at least two more weeks before we could have an option to play him, and we’ll start testing that out sooner than later.”