Saints QB Derek Carr back in concussion protocol, his 2nd concussion in a month

Derek Carr had a rough Sunday in more than a few ways.

Carr's New Orleans Saints fell behind early against the Detroit Lions, and Saints fans were booing him. He was hit hard on a few plays, and one hit he took finished his day. He suffered a rib injury, and Saints coach Dennis Allen said Monday Carr's in the concussion protocol.

Most players who have been through the concussion protocol this season have not played that same week. What complicates Carr's case this week is it's his second concussion in less than a month. He suffered a concussion Nov. 12 against the Minnesota Vikings.

Carr also suffered a shoulder injury, though Allen didn't seem concerned about that. If Carr doesn't start this week, Jameis Winston would start in his place against the 1-11 Carolina Panthers.

Carr has had an up-and-down season, which was a reason for fans booing him Sunday. The Saints are 5-7, which is disappointing considering their talent and being in a weak NFC South. The Saints have struggled in the red zone, which has reflected poorly on Carr. Carr signed a $150 million deal in the offseason and the Saints can't be happy with the return so far. Carr's injuries are another obstacle in a rough first season in New Orleans.