[Update: ESPN's Adam Schefter reports Jamaal Charles tore his ACL which, if accurate, would end his 2011 season.]
In the first quarter of Sunday's game between the Kansas City Chiefs and Detroit Lions -- before it turned into a total blowout -- RB Jamaal Charles sprinted to the right sideline and stretched his left leg to try and reach the first down marker.
His foot stepped on the first down marker on the sidelines and his knee appeared to buckle and he hit the turf tumbling into the Lions mascot.
Charles immediately clutched his left knee and appeared to be in a lot of pain. The Chiefs trainers came out and eventually wheeled him off the field on a cart.
As you can tell in the photo above, Charles was visibly upset after the play.
Charles was out for the rest of the game and the injury definitely looked like a serious one but, as of now, we don't have any credible reports on the severity of his injury. Will Carroll of SI.com tweeted this out shortly after 4:00 p.m. (Arrowhead Time):
Just told Jamaal Charles heading (headed?) for MRI. No official word on knee yet.
We can hold out hope that this isn't serious. We just don't know yet.