Elsa/Getty Images Rasul Douglas of the Buffalo Bills takes the field prior to playing the Denver Broncos during the AFC Wild Card Playoffs at Highmark Stadium on January 12. The San Francisco 49ers missed out on Jalen Ramsey, but there are still options for them to upgrade their secondary. According to ESPN, three of the top-four remaining free agents are cornerbacks, and signing any would constitute an improvement to the Niners cornerback room. After losing Charvarious Ward to the Indianapolis