The Kansas City Chiefs quarterback Alex Smith has a lacerated spleen and will miss their regular-season finale against the San Diego Chargers.
San Diego can make the playoffs with a victory in the game at Kansas City, who have slim post-season hopes depending on other results.
Smith was hit in the abdomen in last week's loss to the Pittsburgh Steelers and tests revealed the laceration.
"They pushed me to get checked out and I got the call that I had the laceration on there and it was enlarged," Smith, who had practiced earlier in the week, told reporters.
Chase Daniel will start for the Chiefs. The backup's only previous NFL start came against the Chargers last year, a game San Diego won to make the playoffs.
The playoff-bound Arizona Cardinals also will be using backup Ryan Lindley again in their game against the San Francisco 49ers.
Lindley, who became the Cardinals starter after Drew Stanton was injured, was ineffective in a 35-6 loss to Seattle last week.
Arizona can win the NFC West with a win at the San Francisco 49ers and a loss by the Seattle Seahawks, who are at home to the St. Louis Rams. Seattle will claim the title if they beat St. Louis and Arizona loses.
Three other division crowns are up for grabs on Monday (NZ time), the final day of the NFL regular season.
Either the Cincinnati Bengals or Pittsburgh Steelers will win the AFC North in their showdown at Pittsburgh.
The NFC North title will go to the winner of the game between the Detroit Lions and Green Bay Packers while the NFC South will go to the winner of the Carolina Panthers-Atlanta Falcons game.