Romeo Crennel has spent three weeks trying to figure out when star cornerback Brandon Flowers would return to the practice field. (Getty Images)

Brandon Flowers' heel injury has become the unsolved mystery of the Chiefs preseason. 

Flowers injured his left heel on July 31 in a night practice and was carted off the field. Coach Romeo Crennel thought the cornerback would return "soon" from what was thought to be a foot injury. That was on Aug. 2. Soon has turned into 23 days, and counting...

As the Sept. 9 season opener against Atlanta creeps closer, only two things are clear when it comes to Flowers' status: Crennel really wants Flowers back, and he has no idea when that is going to happen.

To really see the oddity of this prolonged absence -- and the chances of it continuing right up until the opener -- it helps to see the timeline of Crennel's reports to the media, all via the Kansas City Star.

On Thursday, Aug. 2

"We'll treat it and rest it and then he'll get back out there pretty soon, hopefully," Crennel said. 

On Monday, Aug. 13

"He's getting better, but it's not where he wants it to be yet, and having to do the job he has to do. He's rehabbing and he’s working at it, and hopefully one day, he’ll come out, and all of a sudden, 'Boom,' he'll feel great, and he'll be ready to go, because they tell me those bruises hurt for a little bit, and all of a sudden they just disappear."

On Tuesday, Aug. 14

Flowers is not at practice because he's visiting with doctors for further evaluation -- he had been on the sidelines watching practice every day until this point. 

"Any time you're not able to practice, your timing, your recognition of routes, your condition is not what it needs to be. We'd like to get him out there so that those things can get into game shape," Crennel said. "That's what we need him to be. We need him to be in game shape. When that first game comes, they don't care what kind of problems you might have had or anything like that. If you're on the field, you're expected to produce. So we've got to get him on the field and get sharp so he can perform at a high level.

"Tomorrow, if he doesn't do anything then you can probably rule him out [against St. Louis on Aug. 18]. If you don't practice, it's hard to play in the game. At that time, you might be exposing him to more injury risk.”

On Thursday, Aug. 16:

"It's just one of those things that they haven't been able to pinpoint exactly why he's not getting better as fast as we want him to get better.

"He's still working to try to get better. I saw him this morning, and he's doing all that he can. We’re sending him to the doctors, and we're trying different things to try and get it better. He’s getting better slowly, not fast enough, but all we can do is kind of hang on and see what happens."

On Sunday, Aug. 19

"He got treatment over the weekend. We'll see Monday what he looks like and what he can do."

On Monday, Aug. 20: 

Flowers did not practice. Kansas City Star beat writer Adam Teicher reported that Flowers was in a walking boot. 

On Tuesday, Aug. 21:

"He's not well enough to be out there. We need him out there. He's trying to get there, we're doing everything we can, and the doctors have been looking at him to try to figure out how we can get him out there. We'll keep working, he'll keep working and hopefully it will get done before too long."

Romeo, take a breath.

It has been an exhausting 23 days for the Chiefs head coach. The fact that Flowers has been out longer than anticipated and was in a walking boot this week does not rule him out for the season-opener against Atlanta. But it's not a good sign. 

Crennel certainly hopes that Flowers will practice any day now. But at this point, we're all just confused bystanders -- even Crennel.

Follow Chiefs reporter C.J. Moore on Twitter @CBSSportsNFLKC and @cjmoore4.