Two very interesting off-field stories emerged Friday as the Detroit Lions completed preparation for Sunday's game at the Minnesota Vikings.

Free agent cornerback Stanford Routt, released in a surprise earlier this week by the Kansas City Chiefs, visited and worked out for Lions officials. Meanwhile, the Lions and receiver Calvin Johnson painfully tried to get on the same public page about his physical condition. We'll take the stories in that order.

Stanford Routt was released by the Chiefs before getting through one season of a three-year deal. John Rieger/US Presswire

Routt has been released by two teams in the past nine months, and the Chiefs' decision to part ways with him -- not long after signing him to a $19 million contract over three years -- raises a red flag. But in the context of Week 10, when acquired players rarely make an impact of any kind, signing Routt would be a no-brainer for the Lions.

They have already lost rookie cornerback Bill Bentley for the season, leaving them with Chris Houston, Jacob Lacey and rookie Jonte Green as their top three corners. Veteran Drayton Florence could return soon from a broken arm, but the Lions are still one injury away from a really thin situation.

Routt left the Lions' facility without a contract, and it's possible he will continue meeting with teams before determining a landing spot. That's a standard approach for veterans who are midseason free agents. That can't be said for the unusual situation between the Lions and Johnson, however.

As you probably know, Johnson said earlier this season that he suffered a concussion on a hit by the Vikings' Chad Greenway on Sept. 30 at Ford Field. The Lions repeatedly denied his self-diagnosis, saying he passed all tests administered immediately after the hit and in the following days.

Johnson, however, had not recanted his statement since the Lions' denial, and on Thursday he added another layer to his health status. Asked about several high-profile drops this season, Johnson said he suffered nerve damage against the Vikings, making it more difficult than usual to clasp the ball.

The Lions had never acknowledged such an injury on their daily injury report, and on Friday they issued a statement -- along with one from Johnson -- that said he suffered a "stinger," not nerve damage. The Lions also reiterated that Johnson was never diagnosed with a concussion, with which Johnson agreed.

In his statement, Johnson said in part: "I am aware that I did not suffer a concussion in our game against the Vikings earlier this year. I misused the terms 'nerve damage' and 'concussion.'"

I guess I can understand Johnson confusing "nerve damage" with a "stinger," mostly because they're closely related and also because the distinction is irrelevant relative to his larger point. A "stinger" is a non-medical description for an injury to nerves in the shoulder. The Mayo Clinic refers to as a brachial plexus injury, which is defined as an injury to "the network of nerves that sends signals from your spine to your shoulder, arm and hand."

So whether Johnson had "nerve damage" or a "stinger," it stands to reason the injury could impact his ability to catch the ball.

The concussion issue seems more complicated, especially because we are asked to believe that a player of Johnson's intelligence misused the term "concussion." There is of course a difference between a "concussion" and being hit hard, and I suppose Johnson might not have drawn that medical distinction.

I understand why the Lions or any other team would be sensitive to the idea that a player was either allowed to return to a game with a concussion, or was misdiagnosed in the first place, and that's assuredly why the Lions felt compelled to issue this statement. Why the Lions had to convince Johnson he had not suffered a concussion can be explained only by information we don't have at the moment. But something tells me Johnson won't be commenting much on his physical condition again anytime soon.