NEW YORK -- The Braves finally know what's been causing Martin Prado's headaches. Now they simply must wait for them to cease.

Prado's visit to an Atlanta neurosurgeon on Wednesday revealed that the infielder is suffering from "exertional headaches," which will prevent him from rejoining the team in New York. He has begun to take anti-inflammatory medication, and -- pending a reduction of his symptoms -- will reconnect with the team on Friday in Atlanta.

A Braves spokesman said that the club does not believe a stint on the disabled list will be necessary.

Prado, who left Saturday's game with what the Braves originally thought to be heat-related issues, took batting practice and fielded ground balls on Tuesday, with no sign of the headaches that had bothered him earlier in the week. But after fouling a ball off in his first at-bat, Prado felt a sudden recurrence of what manager Bobby Cox called "a piercing pain." He promptly left the game and flew to Atlanta.

"It's worrisome," Cox said prior to Wednesday's game. "You're just wondering what's causing something like that."

Adam LaRoche started at first base on Wednesday against the Mets and should continue to do so until Prado is well enough to play.

Prado was batting .309 in 92 games this season, enjoying the most extended playing time of his four-year career.