FILE - In this Aug. 3, 2010, file photo, San Francisco 49ers tight end Vernon Davis smiles during NFL football training camp in Santa Clara, Calif. Davis signed a five-year extension with the San Francisco 49ers on Saturday making him the highest-paid tight end in NFL history. (AP Photo/Jeff Chiu, File)

Photo by: Jeff Chiu

FILE - In this Aug. 3, 2010, file photo, San Francisco 49ers tight end Vernon Davis smiles during NFL football training camp in Santa Clara, Calif. Davis signed a five-year extension with the San Francisco 49ers on Saturday making him the highest-paid tight end in NFL history. (AP Photo/Jeff Chiu, File)