Oakland Raiders' Derek Carr was mic'd up when he suffered the injury
Players wearing microphones during games offer an interesting insight as to how they operate on the pitch.
Some of course are more vocal than others, but most tend to forget that they are mic'd up so you really do get a sense of passion and urgency on the pitch. It's a gimmick that has been most popular in the NFL and some rugby teams have got on board with it over the last 12 months.
With all the analysis that goes on behind the scenes, player mics are probably the closest fans will get to the action be it on the line of scrimmage or in the middle of a scrum.
And in most cases, players wearing microphones perform without any trouble.
Derek Carr of American NFL team, the Oakland Raiders, wasn't as fortunate.
The quarterback was in the midst of the action on Christmas Eve as the Raiders faced the Indianapolis Colts. Carr was sacked by pass rusher Trent Cole and seemed to signal that there was a problem on the pitch.
"It's broke," he repeats as he sits on the ground and waits for medical attention from the sidelines. The play in question happens at 3:30 of the video.