The Mets have placed closer Bobby Parnell on the 15-day DL with a herniated disk in his neck. The move is retroactive to July 31. Infielder Wilmer Flores has been recalled from Triple-A Las Vegas to fill the roster spot. Parnell 28 has not pitched in a week due to continued discomfort in his neck. He received a cortisone shot on Monday and is eligible to be activated off the DL next Thursday. It's unclear if he'll be ready by then. Manager Terry Collins indicated surgery was a possibility. In 49 games before the injury Parnell went 22 for 26 in save chances with a 2.16 ERA and 3.67 K/BB. He owns a 3.55 ERA in parts of six big-league seasons though this is his first as the team's undisputed closer. Right-hander and former Mariners closer David Aardsma figures to take over ninth-inning duties during Parnell's absence. He has a 3.70 ERA and 2.20 K/BB in 24 1/3 innings for New York this season. Aardsma saved 69 games for the Mariners from 2009-10 but made just one appearance from 2011-12 due to hip and Tommy John surgeries.