Peter King of SI.com wonders aloud if Indianapolis Colts’ quarterback Peyton Manning will be ready to play by Week 1 of the NFL season after having an infected bursa sac near his left knee removed in mid July.

After surgery, the knee was immobilized — for two weeks, I was told — and the infection treated with antibiotics to be sure it was totally eradicated from Manning’s system. “Then the incision had to heal,” said Polian. “That’s fine now. Now he begins — he’s begun — range-of-motion exercises. He’s in that process now. Now he’s at the point where Mother Nature has to take over. He’s close to optimum range of motion now. He’s on schedule, with no bumps in the road.”

Here’s the big problem, as I see it. Polian says the doctors are not going to clear Manning unless they’re sure he can maneuver in the pocket and has the leg strength to play an NFL game. Now, if Manning spent the second half of July (or more) with the leg immobilized, with a little longer to wait before normal activity could be resumed, the resulting muscle atrophy would take a while to get over. Thus, as of Sunday, Manning was working hard to make sure he get could full range of motion and normal flexion in the knee.

Considering he’s never missed a game in his career, the Manning-bursa sac story has been a relatively quiet one so far this summer. But King is right – this might become a huge issue in about a week if Manning can’t practice. In terms of being familiar with the playbook and offense, obviously Manning has zero learning curve to worry about seeing as how he knows Tom Moore’s system like the back of his hand. But it’s a different animal when you consider Manning still has to get his timing back with his receivers and get his legs ready for a full 16-game season.

It’s easy to say, “Well it’s Peyton Manning – he’s going to play.” But even if he does, will he be 100%? There has to be some concerns brewing within the Colts’ organization, even if they do believe Jim Sorgi (who has never started an NFL regular season game) is a capable backup.