Before getting to the worst of the worst, let's look at a few unknowns that will become clearer in the days ahead. Please note that this list is not comprehensive.
Philadelphia Eagles QB Michael Vick (Hamstring)
According to Josh Alper of Pro Football Talk, Vick aggravated a previous hamstring injury on Sunday, writing that the quarterback felt his hamstring "pop."
The significance of that pop remains unclear.
Frequently, an athlete feels a pop with an injury when a muscle tendon or ligament gives way completely, but Vick stated that this one did not feel as bad as previous injuries. A Monday MRI will show more detail and allow for the formation of a prognosis.
Tampa Bay Buccaneers WR Mike Williams (Hamstring)
Williams told Ira Kaufman of The Tampa Tribune that he has a torn hamstring. The injury first occurred in September.
It's sometimes difficult to interpret the words "torn," "pulled" and "strained" in the media.
If Williams does have a complete hamstring tear—a grade-three strain—he may need surgery. However, a partial tear could heal with rest and rehab.
Further updates will surely follow this week.
Denver Broncos TE Julius Thomas (Ankle)
The Denver Post's Mike Klis tweeted Thomas left Sunday's matchup against the Washington Redskins early with an ankle injury.
Presumably, the injury is a sprain, though precise details are not yet available.
Klis mentions the tight end has a history of ankle issues. That may come into play, as repeated ankle injuries can lead to instability and the need for further intervention, up to and including surgery.
Fortunately, nothing yet suggests Thomas will go down that route, and more information should become available soon.
Dallas Cowboys G Brian Waters (Triceps)
Tom Orsborn of the San Antonio Express-News tweeted that Waters had a triceps injury early in Sunday's game against Detroit.
Details are scarce, but a full triceps tendon tear would likely require surgical repair and cost Waters the rest of the season.
On the other hand, players can sometimes play through partial injuries, as the 49ers Justin Smith did last year.