Alex Marvez of is reporting that the Buffalo Bills have agreed to re-sign cornerback Leodis McKelvin to a four-year, $20 million contract. Ian Rapoport of has since learned that the contract includes $7.5 million guaranteed. McKelvin, who will turn 28 just prior to the start of the 2013 regular season, has emerged as one of the NFL's best punt returners over the last two seasons, returning 31 punts at 18.9 yards per clip with three touchdowns in that time frame. The deal also contains enough total money to reasonably pencil McKelvin in as a starting cornerback entering the 2013 season, though he'll likely be competing with others (Aaron Williams chiefly) for that role.