WASHINGTON -- Mike Gonzalez boarded a plane headed for Atlanta on Wednesday night, wondering how a pain-free elbow could have anything to do with the severe drop in velocity that he experienced on Tuesday night.

Still, without even the slightest hint of what could be wrong with his left elbow, the Braves felt it was in everyone's best interest to at least give him a couple weeks of rest. They placed the left-handed reliever on the 15-day disabled list and filled his roster spot by recalling left-handed reliever Macay McBride from Triple-A Richmond.

Gonzalez will be examined by one of the Braves doctors in Atlanta on Thursday, and he'll likely undergo another MRI exam. The one that he had on April 19 showed no structural damage, and since that point in time, he had displayed the successful form that allowed him to convert each of his 24 save opportunities for the Pirates last year.

"It's hard to explain," Braves manager Bobby Cox said. "He said he didn't feel any bit of pain whatsoever."

During the eighth inning of Tuesday's game against the Nationals, Gonzalez's fastball never got above 84 mph. Just four days earlier in Pittsburgh, it had been regularly clocked at 93 mph.

After watching Gonzalez surrender a triple and give up two fly balls to the three Nationals batters that he faced, Cox removed the former closer and sent him to the clubhouse for further examinations.

Multiple hands-on tests didn't reveal any structural damage. But while washing his hair in the shower, Gonzalez's elbow began to spasm. Still, Cox doesn't know for sure if there was any ensuing discomfort.

"He left my office and said he felt, 'No pain, no nothing,'" Cox said. "He went and showered, tried to do something with his hair and his arm went into spasms."

As he spoke late Tuesday night, Gonzalez indicated he wasn't feeling any of the discomfort that he'd had in the past. He missed the final five weeks of last season with elbow tendinitis and then during the first three weeks of this season, he again felt some slight pain.

Without that same discomfort present, he was left with bewilderment.

"I've got to figure out what's going on," Gonzalez said. "I don't know what else to say about that."

After Tuesday's game, some Braves indicated that Steve Avery wasn't complaining of discomfort when he suddenly lost his velocity more than a decade ago. He was never able to regain the dominant form that he had at the beginning of his once promising career.

"It can happen," Cox said.

During his first seven appearances of the season, Gonzalez worked 6 1/3 innings, allowing eight hits, issuing six walks and registering four strikeouts.

In the 10 appearances that followed his first MRI and preceded Tuesday night, he had worked 10 innings, allowing six hits, issuing two walks and registering nine strikeouts.

With Gonzalez out of the mix, Rafael Soriano will work as closer Bob Wickman's only primary setup man. The only current left-hander in the Braves' bullpen is McBride, who has seemingly regained the control that he lacked in Atlanta at the beginning of this season.

During seven appearances at Richmond, five of which were starts, McBride completed 23 innings and posted a 3.13 ERA. In the process, he notched 24 strikeouts and issued seven walks.

After issuing 11 walks in the first three innings he completed for the Braves this year, McBride was sent to Richmond to refine his mechanics. By giving him starts, the Braves gave him the opportunity to work on multiple pitches in differing situations over multiple innings.

Because McBride threw 90 pitches in a five-inning effort on Monday, he likely won't be available to pitch until at least Thursday.

"He might be able to pitch [Thursday] a little bit," Cox said.