(Renton, WA)  --  The Seattle Seahawks defense now leads the NFL in the category of yards allowed.  The Hawks will need to rely on that defense Thanksgiving night, when they take on Colin Kaepernick and the San Francisco 49ers.  Head coach Pete  Carroll says Seattle came out injury-free from the win Sunday over the Arizona Cardinals, except for a sprained ankle suffered by tight end Cooper Helfet.  Kickoff Thursday in Santa Clara is set for 5:30 p.m.