FILE - In this Sept. 25, 2016, file photo, Kansas City Chiefs linebacker Derrick Johnson smiles during a news conference following an NFL football game against the New York Jets in Kansas City, Mo. Players such as Johnson, who is entering his 13th season, are about as rare as the I-formation in an era when the NFL Players’ Association reports the average career lasts just over three years. (AP Photo/Ed Zurga, File)