Le'Veon Bell, RB, Pittsburgh Steelers.
While the country began to enter Thanksgiving's tryptophan-induced food comas—which, by the way, are nothing more than a myth*—NFL players took the field to kick off Week 13.
Unfortunately, injuries followed close behind.
A number of key players went down during Thursday's action, and the ramifications will become more apparent in the coming days as teams conduct further exams and MRIs.
Let's take a look, starting with those from the early game—Green Bay versus Detroit—and continuing on into the late-afternoon and evening matchups.
*As mentioned, the notion that consuming tryptophan causes sleepiness is a myth. More than likely, eating unusually large quantities of food on Thanksgiving diverts a greater proportion of blood and energy to the digestive system, leading to drowsiness. In fact, according to this article by Lisa Zamosky of Web MD, turkey actually contains less tryptophan than, say, chicken.
Evan Dietrich-Smith, C, Green Bay Packers.
Evan Dietrich-Smith, C (knee)
According to ESPN's Rob Demovsky, Dietrich-Smith went down with a knee injury in the second quarter on Thursday—his second in less than a month.
Needless to say, a "knee injury" is not a very specific diagnosis, and further details will likely emerge soon.
The amount of missed time can range from none at all to much, much longer. Physical exams and, if indicated, an MRI will clarify a prognosis.
Ryan Taylor, TE (possible concussion)
Taylor found himself on the receiving end of a helmet-to-helmet collision with Detroit's DeAndre Levy, and the official Packers Twitter account had the news of his possible concussion shortly thereafter.
In the locker room, doctors and medical staff likely examined Taylor's memory, balance and orientation to place and time, among other criteria. The existence of significant abnormalities implies a concussion.
If doctors made such a diagnosis, the Packers tight end cannot return to the field before completing the NFL's standardized return-to-play protocol, a process that requires at least three days—and often more.
Calvin Johnson, WR, Detroit Lions.
Fortunately, the Detroit Lions avoided serious injuries during their 40-10 blowout of the Green Bay Packers. However, the Motor City briefly held its collective breath when superstar wide receiver Calvin Johnson arose from the ground slowly at one point on Thursday.
According to Lions senior writer Tim Twentyman, Johnson received medical attention on the training table during the game.
Luckily, he quickly returned. With Detroit's next game on Dec. 8, there is no reason to expect any missed time at this point.
Rashad Jennings, RB, Oakland Raiders.
Mike Brisiel, G (knee)
Details are lacking, but the official Raiders Twitter account reported Brisiel sustained an unclear knee injury on Thursday. Further testing, up to and including an MRI, may prove necessary in the coming hours and days.
In the best-case scenario, an extended layoff between games may help Brisiel return for Week 14, but knee injuries are never a guarantee—and often quite the opposite.
Mike Jenkins, CB (shoulder)
Jenkins took some unfortunate friendly fire when a teammate contacted him in the head and neck area. Though he briefly returned to the game, TV cameras then showed him heading to the locker room.
The Raiders Twitter account later announced a shoulder injury.
The exact injury Jenkins suffered remains unclear, and the differential diagnosis remains broad. A stinger—where the nerves in the neck stretch and cause numbness or weakness in the arm or shoulder on the same side—is one definite possibility. Usually, stinger symptoms resolve quickly—but not always.
A mild shoulder contusion or sprain is also high on the list of possibilities.
Rashad Jennings, RB (concussion)
A brutal knee to the side of the head possibly caused Jennings to lose consciousness late in the afternoon Thursday. He briefly lay face-down on the ground motionless after the hit.
After medical staff tended to him and brought him to his feet, a dazed facial expression and poor balance became immediately apparent, confirming the concussion diagnosis.
Jennings must complete the NFL's concussion protocol before returning to the field. With nine days to do so, he has a decent chance to play Week 14, but he needs to overcome many obstacles before doing so.
Safety Usama Young: Shoulder, according to the Raiders Twitter account
Lance Dunbar, RB, Dallas Cowboys.
Lance Dunbar, RB (knee)
Dunbar sustained a hyperextended left knee toward the end of Dallas' matchup with the Raiders. A diagnosis of a knee sprain surfaced on the Cowboys Twitter account soon after.
A knee hyperextension is a mechanism of injury—not a diagnosis. It can range from a very serious injury to nothing much at all.
ESPNDallas.com's Calvin Watkins offered some reassurance later in the evening. According to Watkins, Dunbar did not have ice on his knee when talking with reporters after the game, a sign that significant swelling was not present at the time.
Nevertheless, Pro Football Talk's Twitter account shut down any growing optimism Friday afternoon, announcing Dunbar needs surgery—one that will likely end his season—to fix a posterior lateral corner injury. In other words, the running back sustained significant damage to one or more structures at the back-outside corner of his knee.
Le'Veon Bell, RB, Pittsburgh Steelers.
Le'Veon Bell, RB (head/neck)
Bell went down at the end of the Steelers' contest with the Ravens Thursday night. He appeared to lose consciousness after a helmet-to-helmet hit knocked his helmet from his head. His neck hyperextended soon thereafter when he contacted the ground.
Fortunately, he rose to his feet after only a brief moment—obviously stunned but walking with only some assistance.
The announcement of a concussion diagnosis is a formality at this point. A cervical spine sprain—similar to whiplash in this case—is also possible.
Bell likely underwent or will undergo X-rays or CT scans of his cervical vertebrae shortly after the injury. An MRI may follow, after which he must start his own concussion return protocol over the coming days. The existence of any other soft tissue, bone or ligament injury may complicate his recovery.
That said, given how it initially looked, the NFL community can breathe a sigh of relief.
Brett Keisel, DE (foot)
Keisel left Thanksgiving's action with a foot injury, the details of which remain scarce.
According to 970 ESPN Pittsburgh's David Todd, the injury did not involve contact and occurred when Keisel pushed off the ground. Such an injury mechanism sometimes suggests an Achilles tear, but no reports of such an injury yet exist.
The Steelers lineman recently suffered from plantar fasciitis. His recent setback may constitute an aggravation of the injury or the completion of a partially torn plantar fascia. Details should come soon.
Emmanuel Sanders, WR (no significant injury)
Sanders fell with most of his weight on his left shoulder early on Thursday evening. He remained on his knees for some time before missing minimal time.
The Steelers wideout likely only had the wind knocked out of him. Falling hard on one's side can apply significant pressure to the abdomen, causing the diaphragm to briefly go into spasm.
A spastic diaphragm makes breathing quite difficult. Usually, it resolves within a few seconds to a minute or two—as it did in this case.
Fernando Velasco, C (unclear leg injury)
Velasco went down late with an unclear injury. TV cameras caught him requiring assistance to leave the field.
Mark Kaboly of the Pittsburgh Tribune-Review later tweeted the center required a walking boot after the game.
Depending on suspicions, medical staffs use walking boots to protect and immobilize the foot and ankle. An ankle sprain or fracture is possible, but the precise nature of the injury is not yet known.
T Kelvin Beachum: Knee, according to Matt Vensel of The Baltimore Sun
Brandon Stokley, WR, Baltimore Ravens.
Elvis Dumervil, C (ankle)
Dumervil went down with an ankle injury but later returned, according to ESPN.com's Jamison Hensley. Presumably, he sustained a minor sprain.
Ankle taping can provide additional support to an injured ankle, thereby lessening the chance of a second, aggravating injury. He will surely take advantage of the long layoff before the next Ravens game on Dec. 8.
Jimmy Smith, CB (possible concussion)
The Yahoo! Sports Twitter account noted Smith seemed woozy after his collision with Le'Veon Bell.
Smith likely underwent concussion testing. If doctors diagnosed the injury, a trip to the concussion return protocol awaits.
Brandon Stokley, WR (knee)
According to the Ravens Twitter account, Stokley sustained a significant knee injury during Thursday's action.
Similar to other unclear knee injuries, additional information may come via MRI on Friday.
Both wide receivers Jacoby Jones and Torrey Smith sat out with various injuries but later returned to the field. Neither condition seemed serious.
Dr. Dave Siebert is a resident physician at the University of Washington. Find more of his written work at the Under the Knife blog.
Injury analyses contained in this slideshow are based on the author's own viewing of the three Thanksgiving games—with supplementation from the cited sources when necessary.