Bobby Parnell, who has emerged as a steady closer for the New York Mets, landed on the disabled list before Tuesday's series opener against the Colorado Rockies with a herniated disk in his neck.

Parnell has suggested that sleeping awkwardly on the last road trip triggered the issue, not a baseball-related activity.

"It's pushing on a nerve. So we've got to get the inflammation out of there and take it one day at a time, see how it goes," Parnell said.

"It's just a holding pattern right now. We'll see what happens. If it works the first time, that's great. I think you can have up to two epidurals. I'm going to try that until I can't anymore. If it doesn't work, then surgery is an option. If I do have surgery, they said I'll be ready for spring training next year. It's just a waiting game right now.

"The first day it came about was the second day in Miami (July 30). I just thought I slept on it wrong or something like that. What really what first caused it was a spasm. I felt it and thought it was a muscle spasm. The training staff worked through it for me, got me ready for the game. I pitched in the game. I had the next day off, just relaxing and everything. It was pretty sore. The third day is I guess when the inflammation really caught up and that is when it was causing me a lot of discomfort. I got about three hours of sleep that night. I couldn't lay down. It went from there. I got the MRI and found out I had the herniated disk.

"What it is, is that the herniated disk is hitting the nerve and it's pushing the pain down through there. It's the neck hitting the nerve that's causing discomfort down the arm."

He was re-examined Monday at the Hospital for Special Surgery in Manhattan and received an epidural. General manager Sandy Alderson said surgery remains a possibility.

"He had a series of injections last week. He had an epidural yesterday. And so right now we're simply evaluating how he responds to those two treatments," Alderson said. "We'll know more in the next two or three days. It is conceivable that if those don't work, something more significant, more invasive would have to be considered -- surgery, possibly. But right now we're not at that stage."

Parnell had not appeared in a game since last Tuesday in Miami, so he will be eligible to return from the disabled list Aug. 15, when the Mets open a four-game series against the San Diego Padres at Petco Park.

Manager Terry Collins has no clear-cut alternative as closer in Parnell's absence. Collins tried using former Seattle Mariners closer David Aardsma in the role Friday against the Kansas City Royals, but he suffered a blown save, then surrendered a tiebreaking 12th-inning homer to Justin Maxwell the following day.

Other options are LaTroy Hawkins, rookie Gonzalez Germen and left-handers Pedro Feliciano and Scott Rice.

Parnell being placed on the DL did open a spot for the Mets to address another void.

The Mets promoted prospect Wilmer Flores on his 22nd birthday. Flores, who had a Pacific Coast League-leading 86 RBIs with Triple-A Las Vegas, likely will play third base while David Wright is on the DL with a Grade 2 right hamstring strain.

The addition of Flores for Parnell restores the Mets to five position players on the bench. The Mets had been operating with a four-man bench for weeks, since deciding to institute a six-man rotation.

Another roster move should be forthcoming next weekend. Jonathon Niese, returning from a partial tear of the rotator cuff in his left shoulder, is due to make his final minor league rehab start on Tuesday night with Double-A Binghamton.

Niese has indicated he expects to reenter the rotation Sunday, when the Mets conclude a series against the Arizona Diamondbacks.