Orthopedic Surgeon says 'a decrease in workload' is prescription for 49ers Christian McCaffrey

San Francisco 49ers star running back, Christian McCaffrey, has been ruled out for Sunday's game in Minnesota. McCaffrey, of course, did not play in Monday night's win over the New York Jets, either. How long will McCaffrey be out? At this point, it's anyone's guess.

49ers general manager John Lynch joined KNBR on Friday and admitted that IR (Injured Reserve) was a possibility for the NFL's reigning Offensive Player of the Year. "If that's the right thing, it's what we'll do," Lynch said. "We'll consult. We'll, first of all, see how he's doing today after getting a good work session in yesterday, see how he responds. And then, all options now, as Kyle [Shanahan] has said, are on the table. We're going to do what's right for Christian, right for our team."

On Tuesday, Shanahan spoke like injured reserve was not an option for McCaffrey. "No, I've never considered that. I was considering him to play [on Monday night], so definitely not thinking about four weeks off." But after ruling him out for Sunday's game, Shanahan changed his tune. "It's something we're considering now," Shanahan said. "Yeah, yesterday was his worst day. It's on and off, but with yesterday having the most pain, it's something we're going to be discussing here the next 24 hours."

So what exactly is the injury McCaffrey is dealing with? Can it get worse? How long might he be out? These are questions 49ers fans are asking. Certainly, the 49ers need to tread lightly, especially considering what happened to star LB Dre Greenlaw, who after dealing with Achilles issues last year, ruptured his Achilles while returning to the field during the Super Bowl.

Dr. Nirav Pandya, Professor of UCSF Orthopedic Surgery and Director of Sports Medicine at Benioff Children's Hospital, took to social media this week and explained how an Achilles injury is related to a calf injury, which was the first injury McCaffrey was said to be dealing with. "Tendonitis is inflammation of the structures that connect muscles to bones," Dr. Pandyasaid. "Most commonly this occurs due to repetitive overuse or injury. The goal is to prevent this from progressing to tendinosis in which the collagen in the tendon begins to break down/degenerate (becoming a chronic issue) or progressing to a complete rupture of the tendon. The calf muscles (gastrocnemius and soleus) connect to the heel via the Achilles tendon.

"It therefore is not uncommon for athletes with calf injuries to have involvement of their Achilles or have the injury progress to involving this structure. Treatment involves decreasing inflammation/pain while maintaining flexibility/strength. The cornerstone of treatment is decreasing load/usage. Return-to-play timelines are difficult to predict as the severity can vary based on the degree of inflammation and pre-existing damage to the tendon."