NEW ORLEANS – We will see Sunday if Derek Carrier is ready to be the San Francisco 49ers' new Swiss Army Knife.The 49ers promoted Carrier from the practice squad to the 53-man roster. Third tight end Garrett Celek is doubtful with a hamstring injury. Starter Vernon Davis hasn't been cleared to play against the New Orleans Saints, although he is expected to be.Expect Carrier to play Sunday. The team wouldn't have promoted him if it weren't planning to play him.