Weber was recalled from Triple-A Gwinnett on Monday.
The right-hander is replacing Gordon Beckham (hamstring) on the 25-man roster after Beckham was placed on the 15-day disabled list. Weber pitched well in 8.1 innings in the minors this season, which warranted a call-up to the big leagues. Given how badly the injury bug has bitten the Braves bullpen so far this season, Weber could get a decent number of chances to pitch for Atlanta during his time in the big leagues.