Carolina Panthers linebacker Luke Kuechly has been ruled out of his side's match against the Houston Texans.
The 24-year-old sustained a concussion in his side's win over the Jacksonville Jaguars last week, and was unable to return to practice during the week.
Kuechly failed to pass the protocol concussion test required by the NFL to return to the field, and as a result he will miss the first match of his four-year career.
The linebacker recorded seven tackles and one sack in his side's win over the Jaguars.